| 1 | !! Copyright (C) 2004-2011 M. Oliveira, F. Nogueira |
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| 2 | !! |
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| 3 | !! This program is free software; you can redistribute it and/or modify |
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| 4 | !! it under the terms of the GNU General Public License as published by |
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| 5 | !! the Free Software Foundation; either version 2, or (at your option) |
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| 6 | !! any later version. |
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| 7 | !! |
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| 8 | !! This program is distributed in the hope that it will be useful, |
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| 9 | !! but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 10 | !! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 11 | !! GNU General Public License for more details. |
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| 12 | !! |
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| 13 | !! You should have received a copy of the GNU General Public License |
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| 14 | !! along with this program; if not, write to the Free Software |
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| 15 | !! Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
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| 16 | !! 02111-1307, USA. |
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| 17 | !! |
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| 18 | !! $Id$ |
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| 19 | |
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| 20 | #include "global.h" |
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| 21 | |
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| 22 | module wave_equations_integrator_m |
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| 23 | use global_m |
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| 24 | use messages_m |
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| 25 | use io_m |
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| 26 | use gsl_interface_m |
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| 27 | use oct_parser_m |
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| 28 | use quantum_numbers_m |
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| 29 | use potentials_m |
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| 30 | use wave_equations_derivs_m |
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| 31 | implicit none |
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| 32 | |
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| 33 | |
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| 34 | !---Interfaces---! |
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| 35 | |
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| 36 | interface |
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| 37 | function ode_solve(x2, stp, evl, ctrl, h1, hmin, nstepmax, nstep, x, y1, y2, myfunc) |
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| 38 | use global_m |
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| 39 | implicit none |
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| 40 | integer(POINTER_SIZE), intent(inout) :: stp, evl, ctrl |
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| 41 | integer, intent(in) :: nstepmax |
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| 42 | integer, intent(out) :: nstep |
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| 43 | real(R8), intent(in) :: x2, h1, hmin |
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| 44 | real(R8), intent(inout) :: x(nstepmax), y1(nstepmax), y2(nstepmax) |
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| 45 | integer :: ode_solve |
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| 46 | interface |
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| 47 | subroutine myfunc(t, y, f) |
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| 48 | use global_m |
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| 49 | real(R8), intent(in) :: t |
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| 50 | real(R8), intent(in) :: y(2) |
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| 51 | real(R8), intent(out) :: f(2) |
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| 52 | end subroutine myfunc |
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| 53 | end interface |
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| 54 | end function ode_solve |
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| 55 | end interface |
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| 56 | |
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| 57 | |
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| 58 | !---Derived Data Types---! |
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| 59 | |
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| 60 | type integrator_t |
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| 61 | private |
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| 62 | integer :: nstepmax |
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| 63 | integer(POINTER_SIZE) :: evl, stp, ctrl |
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| 64 | real(R8) :: hmin, tol |
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| 65 | end type integrator_t |
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| 66 | |
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| 67 | |
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| 68 | !---Global Variables---! |
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| 69 | |
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| 70 | integer, parameter :: SCHRODINGER = EQ1, & |
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| 71 | DIRAC = EQ2, & |
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| 72 | SCALAR_REL = EQ3 |
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| 73 | |
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| 74 | integer, parameter :: M_RK2 = 1, & |
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| 75 | M_RK4 = 2, & |
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| 76 | M_RKF4 = 3, & |
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| 77 | M_RKCK4 = 4, & |
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| 78 | M_RKPD8 = 5 |
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| 79 | |
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| 80 | |
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| 81 | !Wavefunctions values at infinity |
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| 82 | real(R8), parameter :: SCHRODINGER_FINF = 1.0E-20_r8 |
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| 83 | real(R8), parameter :: DIRAC_FINF = 1.0E-20_r8 |
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| 84 | |
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| 85 | |
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| 86 | !---Public/Private Statements---! |
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| 87 | |
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| 88 | private |
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| 89 | public :: integrator_t, & |
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| 90 | wave_equations_integrator_init, & |
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| 91 | outward_integration, & |
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| 92 | inward_integration, & |
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| 93 | practical_infinity, & |
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| 94 | wave_equations_integrator_end, & |
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| 95 | SCHRODINGER, & |
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| 96 | DIRAC, & |
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| 97 | SCALAR_REL, & |
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| 98 | SCHRODINGER_FINF, & |
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| 99 | DIRAC_FINF, & |
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| 100 | M_RK2, & |
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| 101 | M_RK4, & |
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| 102 | M_RKF4, & |
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| 103 | M_RKCK4, & |
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| 104 | M_RKPD8 |
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| 105 | |
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| 106 | contains |
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| 107 | |
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| 108 | subroutine wave_equations_integrator_init(integrator_sp, integrator_dp) |
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| 109 | !-----------------------------------------------------------------------! |
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| 110 | ! Initializes integrator objects by reading some parameters from the ! |
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| 111 | ! input file and by initializing GSL ODE solver objects. ! |
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| 112 | ! Two objects are initialized: one for single precision integrations ! |
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| 113 | ! and a second one for double precision integrations. ! |
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| 114 | ! ! |
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| 115 | ! integrator_sp - single-precision integrator object ! |
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| 116 | ! integrator_dp - double-precision integrator object ! |
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| 117 | !-----------------------------------------------------------------------! |
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| 118 | type(integrator_t), intent(out) :: integrator_sp, integrator_dp |
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| 119 | |
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| 120 | integer :: stepping_func |
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| 121 | real(R8) :: tol |
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| 122 | |
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| 123 | call push_sub("wave_equations_integrator_init") |
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| 124 | |
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| 125 | message(1) = "" |
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| 126 | message(2) = "Initializing Wave-Equations Integrator" |
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| 127 | call write_info(2) |
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| 128 | |
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| 129 | !Which stepping function will we use |
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| 130 | call oct_parse_int('SteppingFunction', 5, stepping_func) |
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| 131 | select case (stepping_func) |
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| 132 | case (M_RK2) |
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| 133 | message(1) = " Stepping function: Embedded 2nd order Runge-Kutta" |
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| 134 | message(2) = " with 3rd order error estimate" |
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| 135 | call write_info(2,20) |
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| 136 | case (M_RK4) |
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| 137 | message(1) = " Stepping function: 4th order (classical) Runge-Kutta method" |
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| 138 | call write_info(1,20) |
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| 139 | case (M_RKF4) |
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| 140 | message(1) = " Stepping function: Embedded 4th order Runge-Kutta-Fehlberg " |
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| 141 | message(2) = " method with 5th order error estimate" |
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| 142 | call write_info(2,20) |
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| 143 | case (M_RKCK4) |
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| 144 | message(1) = " Stepping function: Embedded 4th order Runge-Kutta Cash-Karp" |
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| 145 | message(2) = " method with 5th order error estimate" |
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| 146 | call write_info(2,20) |
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| 147 | case (M_RKPD8) |
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| 148 | message(1) = " Stepping function: Embedded 8th order Runge-Kutta Prince-Dormand" |
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| 149 | message(2) = " method with 9th order error estimate" |
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| 150 | call write_info(2,20) |
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| 151 | ! case (6) |
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| 152 | ! message(1) = " Stepping function: Implicit 4th order Runge-Kutta at Gaussian points" |
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| 153 | ! call write_info(1,20) |
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| 154 | ! case (7) |
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| 155 | ! message(1) = " Stepping function: M=2 implicit Gear method" |
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| 156 | ! call write_info(1,20) |
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| 157 | case default |
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| 158 | message(1) = "SteppingFunction must be between 1 and 5." |
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| 159 | call write_fatal(1) |
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| 160 | end select |
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| 161 | |
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| 162 | !Read the ODE integrator tolerance |
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| 163 | call oct_parse_float('ODEIntTolerance', 1.0E-6_r8, tol) |
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| 164 | if (tol <= M_ZERO) then |
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| 165 | message(1) = "ODEIntTolerance must be greater than zero." |
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| 166 | call write_fatal(1) |
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| 167 | end if |
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| 168 | write(message(1),'(2X,"ODE Integrator tolerance: ",ES10.3E2)') tol |
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| 169 | call write_info(1,20) |
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| 170 | |
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| 171 | !Read the maximum number of steps the ODE integrator is allowed to take |
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| 172 | call oct_parse_int('MaxSteps', 50000, integrator_sp%nstepmax) |
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| 173 | if (integrator_sp%nstepmax <= M_ZERO) then |
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| 174 | message(1) = "MaxSteps must be greater than zero." |
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| 175 | call write_fatal(1) |
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| 176 | end if |
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| 177 | write(message(1),'(2X,"ODE Integrator maximum number of steps: ",I6)') integrator_sp%nstepmax |
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| 178 | call write_info(1,20) |
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| 179 | |
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| 180 | !What is the minimum step size allowed |
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| 181 | call oct_parse_float('MinimumStep', 1.0E-15_r8, integrator_sp%hmin) |
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| 182 | if (integrator_sp%hmin <= M_ZERO) then |
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| 183 | message(1) = "MinimumStep must be greater than zero." |
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| 184 | call write_fatal(1) |
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| 185 | end if |
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| 186 | write(message(1),'(2X,"ODE Integrator minimum step size: ",ES10.3E2)') integrator_sp%hmin |
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| 187 | call write_info(1,20) |
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| 188 | |
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| 189 | integrator_dp = integrator_sp |
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| 190 | integrator_sp%tol = sqrt(tol) |
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| 191 | integrator_dp%tol = tol**2 |
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| 192 | |
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| 193 | !Initialize GSL objects |
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| 194 | call gsl_odeiv_step_alloc(stepping_func, 2, integrator_sp%stp) |
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| 195 | call gsl_odeiv_evolve_alloc(2, integrator_sp%evl) |
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| 196 | call gsl_odeiv_control_standart_new(integrator_sp%ctrl, 1.0E-22_r8, integrator_sp%tol, M_ONE, M_ONE) |
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| 197 | |
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| 198 | call gsl_odeiv_step_alloc(stepping_func, 2, integrator_dp%stp) |
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| 199 | call gsl_odeiv_evolve_alloc(2, integrator_dp%evl) |
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| 200 | call gsl_odeiv_control_standart_new(integrator_dp%ctrl, 1.0E-22_r8, integrator_dp%tol, M_ONE, M_ONE) |
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| 201 | |
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| 202 | call pop_sub() |
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| 203 | end subroutine wave_equations_integrator_init |
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| 204 | |
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| 205 | subroutine outward_integration(qn, e, wave_eq, wf_dim, potential, integrator, nstep, r_out, wf_out, wfp_out, rc) |
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| 206 | !-----------------------------------------------------------------------! |
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| 207 | ! Integrates the radial wave-equation outward from a point near the ! |
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| 208 | ! origin to the classical turning point. ! |
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| 209 | ! ! |
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| 210 | ! qn - set of quantum numbers ! |
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| 211 | ! e - energy ! |
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| 212 | ! wave_eq - wave-equation to integrate ! |
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| 213 | ! wf_dim - dimension of the wavefunction spinor ! |
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| 214 | ! potential - potential object ! |
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| 215 | ! integrator - integrator object ! |
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| 216 | ! nstep - number of steps taken by the solver ! |
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| 217 | ! r_out - mesh used by the ODE solver ! |
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| 218 | ! wf_out - wavefunction ! |
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| 219 | ! wfp_out - wavefunction derivative ! |
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| 220 | ! rc - if present the integration will stop at rc instead of ! |
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| 221 | ! stopping at the classical turning point ! |
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| 222 | !-----------------------------------------------------------------------! |
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| 223 | type(qn_t), intent(in) :: qn |
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| 224 | real(R8), intent(in) :: e |
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| 225 | integer, intent(in) :: wave_eq, wf_dim |
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| 226 | type(potential_t), intent(in) :: potential |
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| 227 | type(integrator_t), intent(inout) :: integrator |
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| 228 | integer, intent(out) :: nstep |
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| 229 | real(R8), pointer :: r_out(:), wf_out(:,:), wfp_out(:,:) |
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| 230 | real(R8), intent(in), optional :: rc |
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| 231 | |
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| 232 | integer :: ierr, i |
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| 233 | real(R8) :: z, vp0, r0, ri, s, a0, a1, a2, a3, b0, b1, b2, w |
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| 234 | real(R8), allocatable :: r(:), g(:), f(:) |
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| 235 | |
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| 236 | call push_sub("outward_integration") |
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| 237 | |
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| 238 | !Allocate work arrays |
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| 239 | allocate(r(integrator%nstepmax), g(integrator%nstepmax), f(integrator%nstepmax)) |
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| 240 | |
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| 241 | !Get the initial and final points |
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| 242 | r0 = smallest_safe_r(potential) |
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| 243 | if (present(rc)) then |
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| 244 | ri = rc |
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| 245 | else |
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| 246 | ri = classical_turning_point(potential, e, qn) |
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| 247 | end if |
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| 248 | |
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| 249 | ! For a potential v(r) = vp(r) - Z/r, the general solutions of the equations |
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| 250 | ! when r->0 are of the form: |
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| 251 | ! |
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| 252 | ! g(r) = r**(s-1) (a0 + a1 r + a2 r**2 + ...) |
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| 253 | ! f(r) = r**(s-1) (b0 + b1 r + b2 r**2 + ...) |
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| 254 | ! |
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| 255 | ! Schrodinger equation: |
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| 256 | ! s = l |
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| 257 | ! a0 = 0 |
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| 258 | ! a2 = - Z/(l + 1) a1 |
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| 259 | ! a3 = [-Z a2 + (vp - e) a1]/(2l + 3) |
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| 260 | ! b0 = l a1 |
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| 261 | ! b1 = (l + 1) a2 |
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| 262 | ! b2 = (l + 2) a3 |
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| 263 | ! |
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| 264 | ! Scalar-relativistic equation: |
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| 265 | ! s = sqrt(l(l + 1) + 1 - (Z/c)**2) |
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| 266 | ! a1 = [(e + 2c**2 - vp) b0 - Z/c (2e + 2c**2 - vp) a0]/[(2s + 1)c] |
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| 267 | ! a2 = [(e + 2c**2 - vp)(vp - e)/c a0 + (e + 2c**2 - vp) b1 - Z/c (2e + 2c**2 - vp) a1]/[2(2s + 2)c] |
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| 268 | ! b0 = c/Z (s - 1) a0 |
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| 269 | ! b1 = c/Z [s a1 - (e + 2c**2 - vp)/c b0] |
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| 270 | ! b2 = c/Z [(s + 1) a2 - (e + 2c**2 - vp)/c b1] |
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| 271 | ! |
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| 272 | ! Dirac equation: |
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| 273 | ! s = sqrt(k**2 - (Z/c)**2) |
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| 274 | ! a0 = Z/c b0/(s + k) v a0 = - c/Z (s - k) b0 |
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| 275 | ! a1 = [(s + 1 - k)(e + 2c**2 - vp) b0 - Z/c (e - vp) a0]/(2s + 1)/c |
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| 276 | ! a2 = [(s + 2 - k)(e + 2c**2 - vp) b1 - Z/c (e - vp) a1]/(2s + 2)/(2c) |
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| 277 | ! b0 = -Z/c a0/(s - k) v b0 = c/Z (s + k) a0 |
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| 278 | ! b1 = [-(e - vp)/c a0 - Z/c a1]/(s + 1 - k) |
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| 279 | ! b2 = [-(e - vp)/c a1 - Z/c a2]/(s + 2 - k) |
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| 280 | ! |
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| 281 | ! NOTE: for the scalar-relativistic equation and for Dirac's |
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| 282 | ! equation Z=0 is a special case. |
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| 283 | r(1) = r0 |
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| 284 | z = potential_nuclear_charge(potential) |
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| 285 | vp0 = v(potential, r0, qn) + z/r0 |
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| 286 | select case (wave_eq) |
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| 287 | case (SCHRODINGER) |
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| 288 | s = qn%l |
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| 289 | a0 = M_ZERO |
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| 290 | a1 = M_ONE |
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| 291 | a2 = -z/(s + M_ONE)*a1 |
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| 292 | a3 = (-z*a2 + (vp0 - e)*a1)/(M_TWO*s + M_THREE) |
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| 293 | b0 = s*a1 |
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| 294 | b1 = (s + 1)*a2 |
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| 295 | b2 = (s + 2)*a3 |
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| 296 | case (DIRAC) |
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| 297 | if (z /= M_ZERO) then |
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| 298 | a0 = M_ONE |
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| 299 | s = sqrt(qn%k**2 - (z/M_C)**2) |
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| 300 | b0 = M_C/z*(s + qn%k)*a0 |
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| 301 | else |
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| 302 | if (qn%k < 0) then |
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| 303 | s = -qn%k |
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| 304 | a0 = M_ONE |
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| 305 | b0 = M_ZERO |
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| 306 | else |
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| 307 | s = qn%k |
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| 308 | a0 = M_ZERO |
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| 309 | b0 = M_ONE |
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| 310 | end if |
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| 311 | end if |
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| 312 | w = e + M_TWO*M_C**2 - vp0 |
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| 313 | a1 = (w*(s + M_ONE - qn%k)*b0 - z/M_C*(e - vp0)*a0)/(M_TWO*s + M_ONE)/M_C |
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| 314 | b1 = -((e - vp0)*a0 + z*a1)/(s + M_ONE - qn%k)/M_C |
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| 315 | a2 = (w*(s + M_TWO - qn%k)*b1 - z/M_C*(e - vp0)*a1)/(M_TWO*s + M_TWO)/(M_TWO*M_C) |
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| 316 | b2 = -((e - vp0)*a1 + z*a2)/(s + M_TWO - qn%k)/M_C |
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| 317 | a3 = M_ZERO |
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| 318 | case (SCALAR_REL) |
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| 319 | w = e + M_TWO*M_C**2 - vp0 |
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| 320 | if (z /= M_ZERO) then |
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| 321 | s = sqrt(qn%l*(qn%l + M_ONE) + M_ONE - (z/M_C)**2) |
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| 322 | a0 = M_ONE |
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| 323 | b0 = M_C/z*(s - M_ONE)*a0 |
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| 324 | a1 = (w*b0 - z/M_C*M_TWO*(e + M_C - vp0)*a0)/(M_TWO*s + M_ONE)/M_C |
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| 325 | b1 = M_C/z*(s*a1 - w*b0/M_C) |
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| 326 | a2 = (w*(vp0 - e)*a0/M_C + w*b1 - z/M_C*M_TWO*(e + M_C - vp0)*a1)/(M_FOUR*s + M_FOUR)/M_C |
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| 327 | b2 = M_C/z*((s + M_ONE)*a2 - w*b1/M_C) |
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| 328 | a3 = M_ZERO |
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| 329 | else |
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| 330 | if (qn%l == 0) then |
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| 331 | s = M_ONE |
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| 332 | a0 = M_ONE |
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| 333 | b1 = (vp0 - e)*a0/M_THREE |
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| 334 | a2 = w/(M_TWO*M_C)*b1 |
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| 335 | b0 = M_ZERO ; a1 = M_ZERO ; b2 = M_ZERO ; a3 = M_ZERO |
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| 336 | else |
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| 337 | s = qn%l |
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| 338 | b0 = M_ONE |
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| 339 | a1 = w/(s*M_C)*b0 |
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| 340 | a0 = M_ZERO ; b1 = M_ZERO ; a2 = M_ZERO ; b2 = M_ZERO ; a3 = M_ZERO |
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| 341 | end if |
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| 342 | end if |
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| 343 | end select |
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| 344 | g(1) = r0**(s - M_ONE)*(a0 + a1*r0 + a2*r0**2 + a3*r0**3) |
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| 345 | f(1) = r0**(s - M_ONE)*(b0 + b1*r0 + b2*r0**2) |
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| 346 | |
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| 347 | ! MGGA term |
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| 348 | if (wave_eq == SCHRODINGER) then |
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| 349 | f(1) = f(1)*(M_ONE + M_TWO*vtau(potential, r0, qn)) |
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| 350 | end if |
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| 351 | |
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| 352 | !Set the parameters needed to compute the derivatives of the functions |
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| 353 | call set_derivs_params(qn, e, wave_eq, potential) |
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| 354 | |
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| 355 | !Integrate the equation from r0 to ri |
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| 356 | ierr = ode_solve(ri, integrator%stp, integrator%evl, integrator%ctrl, (r0+ri)/M_TWO, & |
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| 357 | integrator%hmin, integrator%nstepmax, nstep, r, g, f, derivs) |
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| 358 | if (ierr /= 0) then |
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| 359 | if (in_debug_mode) then |
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| 360 | call wave_equations_integrator_debug(integrator, r0, ri, nstep, r, g, f) |
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| 361 | call wave_equations_derivs_debug() |
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| 362 | end if |
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| 363 | message(1) = "Error in subtoutine outward_integration. Error message:" |
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| 364 | select case (ierr) |
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| 365 | case (100) |
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| 366 | message(2) = "stepsize underflow" |
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| 367 | case (101) |
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| 368 | message(2) = "integration diverged" |
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| 369 | case default |
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| 370 | call gsl_strerror(ierr, message(2)) |
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| 371 | end select |
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| 372 | call write_fatal(2) |
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| 373 | end if |
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| 374 | |
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| 375 | !Copy the functions to new arrays |
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| 376 | allocate(r_out(nstep), wf_out(nstep, wf_dim), wfp_out(nstep, wf_dim)) |
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| 377 | r_out = r(1:nstep) |
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| 378 | select case (wave_eq) |
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| 379 | case (SCHRODINGER) |
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| 380 | wf_out(1:nstep,1) = g(1:nstep) |
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| 381 | do i = 1, nstep |
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| 382 | wfp_out(i,1) = f(i)/(M_ONE + M_TWO*vtau(potential, r_out(i), qn)) |
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| 383 | end do |
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| 384 | case (SCALAR_REL) |
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| 385 | wf_out(1:nstep,1) = g(1:nstep) |
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| 386 | do i = 1, nstep |
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| 387 | wfp_out(i,1) = (M_TWO*M_C + (e - v(potential, r_out(i), qn))/M_C)*f(i) |
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| 388 | end do |
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| 389 | case (DIRAC) |
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| 390 | wf_out(1:nstep,1) = g(1:nstep) |
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| 391 | wf_out(1:nstep,2) = f(1:nstep) |
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| 392 | do i = 1, nstep |
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| 393 | call derivs(r_out(i), wf_out(i,:), wfp_out(i,:)) |
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| 394 | end do |
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| 395 | end select |
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| 396 | |
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| 397 | !Deallocate arrays |
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| 398 | deallocate(r, f, g) |
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| 399 | |
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| 400 | !Unset the derivatives parameters |
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| 401 | call unset_derivs_params() |
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| 402 | |
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| 403 | call pop_sub() |
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| 404 | end subroutine outward_integration |
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| 405 | |
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| 406 | subroutine inward_integration(qn, e, wave_eq, wf_dim, potential, integrator, nstep, r_in, wf_in, wfp_in) |
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| 407 | !-----------------------------------------------------------------------! |
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| 408 | ! Integrates the radial wave-equation inward from a point at infinity ! |
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| 409 | ! to the classical turning point. ! |
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| 410 | ! ! |
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| 411 | ! qn - set of quantum numbers ! |
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| 412 | ! e - energy ! |
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| 413 | ! wave_eq - wave-equation to integrate ! |
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| 414 | ! wf_dim - dimension of the wavefunction spinor ! |
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| 415 | ! potential - potential object ! |
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| 416 | ! integrator - integrator object ! |
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| 417 | ! nstep - number of steps taken by the solver ! |
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| 418 | ! r_in - mesh used by the ODE solver ! |
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| 419 | ! wf_in - wavefunction ! |
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| 420 | ! wfp_in - wavefunction derivative ! |
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| 421 | !-----------------------------------------------------------------------! |
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| 422 | type(qn_t), intent(in) :: qn |
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| 423 | real(R8), intent(in) :: e |
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| 424 | integer, intent(in) :: wave_eq, wf_dim |
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| 425 | type(potential_t), intent(in) :: potential |
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| 426 | type(integrator_t), intent(inout) :: integrator |
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| 427 | integer, intent(out) :: nstep |
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| 428 | real(R8), pointer :: r_in(:), wf_in(:,:), wfp_in(:,:) |
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| 429 | |
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| 430 | integer :: lpp, ierr, i |
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| 431 | real(R8) :: vinf, kpp, rinf, ri, minf |
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| 432 | real(R8), allocatable :: r(:), g(:), f(:) |
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| 433 | |
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| 434 | call push_sub("inward_integration") |
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| 435 | |
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| 436 | !Allocate work arrays |
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| 437 | allocate(r(integrator%nstepmax), g(integrator%nstepmax), f(integrator%nstepmax)) |
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| 438 | |
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| 439 | !Get the initial and final points |
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| 440 | ri = classical_turning_point(potential, e, qn) |
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| 441 | rinf = practical_infinity(e, wave_eq, integrator%tol) |
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| 442 | |
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| 443 | !Values of the wavefunction and its derivative at infinity |
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| 444 | r(1) = rinf |
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| 445 | select case (wave_eq) |
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| 446 | case (SCHRODINGER) |
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| 447 | g(1) = SCHRODINGER_FINF |
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| 448 | f(1) = -sqrt(-M_TWO*e)*g(1)*(M_ONE + M_TWO*vtau(potential, rinf, qn)) |
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| 449 | case (DIRAC) |
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| 450 | !Values of the wavefunctions at infinity |
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| 451 | lpp = int(qn%j + M_HALF)*(qn%j - M_HALF) |
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| 452 | if (lpp /= 0) lpp = lpp/qn%l |
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| 453 | kpp = sqrt(-e)*sqrt(M_TWO + e/M_C2) |
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| 454 | vinf = v(potential, rinf, qn) |
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| 455 | g(1) = DIRAC_FINF |
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| 456 | |
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| 457 | f(1) = (e - vinf)/M_C* & |
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| 458 | (gsl_sf_bessel_knu_scaled(kpp*rinf, lpp + M_HALF) + (real(qn%k - lpp, R8) - M_ONE)/rinf)/ & |
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| 459 | (kpp*gsl_sf_bessel_knu_scaled(kpp*rinf, lpp + 1.5_r8))*g(1) |
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| 460 | case (SCALAR_REL) |
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| 461 | g(1) = SCHRODINGER_FINF |
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| 462 | vinf = v(potential, rinf, qn) |
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| 463 | minf = M_ONE + (e - vinf)/M_TWO/M_C2 |
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| 464 | f(1) = -sqrt(-M_TWO*minf*e)/(M_TWO*minf*M_C)*g(1) |
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| 465 | end select |
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| 466 | |
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| 467 | !Set the parameters needed to compute the derivatives of the functions |
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| 468 | call set_derivs_params(qn, e, wave_eq, potential) |
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| 469 | |
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| 470 | !Integrate the equation from rinf to ri |
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| 471 | ierr = ode_solve(ri, integrator%stp, integrator%evl, integrator%ctrl, (ri+rinf)/M_TWO, & |
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| 472 | integrator%hmin, integrator%nstepmax, nstep, r, g, f, derivs) |
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| 473 | if (ierr /= 0) then |
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| 474 | if (in_debug_mode) then |
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| 475 | call wave_equations_integrator_debug(integrator, rinf, ri, nstep, r, g, f) |
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| 476 | call wave_equations_derivs_debug() |
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| 477 | end if |
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| 478 | message(1) = "Error in subtoutine inward_integration. Error message:" |
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| 479 | select case (ierr) |
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| 480 | case (100) |
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| 481 | message(2) = "stepsize underflow" |
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| 482 | case (101) |
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| 483 | message(2) = "integration diverged" |
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| 484 | case default |
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| 485 | call gsl_strerror(ierr, message(2)) |
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| 486 | end select |
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| 487 | call write_fatal(2) |
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| 488 | end if |
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| 489 | |
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| 490 | !Copy the functions to new arrays |
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| 491 | allocate(r_in(nstep), wf_in(nstep, wf_dim), wfp_in(nstep, wf_dim)) |
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| 492 | r_in = r(1:nstep) |
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| 493 | select case (wave_eq) |
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| 494 | case (SCHRODINGER) |
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| 495 | wf_in(1:nstep,1) = g(1:nstep) |
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| 496 | do i = 1, nstep |
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| 497 | wfp_in(i,1) = f(i)/(M_ONE + M_TWO*vtau(potential, r_in(i), qn)) |
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| 498 | end do |
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| 499 | case (SCALAR_REL) |
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| 500 | wf_in(1:nstep,1) = g(1:nstep) |
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| 501 | do i = 1, nstep |
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| 502 | wfp_in(i,1) = (M_TWO*M_C + (e - v(potential, r_in(i), qn))/M_C)*f(i) |
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| 503 | end do |
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| 504 | case (DIRAC) |
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| 505 | wf_in(1:nstep,1) = g(1:nstep) |
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| 506 | wf_in(1:nstep,2) = f(1:nstep) |
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| 507 | do i = 1, nstep |
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| 508 | call derivs(r_in(i), wf_in(i,:), wfp_in(i,:)) |
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| 509 | end do |
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| 510 | end select |
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| 511 | |
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| 512 | !Deallocate arrays |
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| 513 | deallocate(r, g, f) |
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| 514 | |
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| 515 | !Unset the derivatives parameters |
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| 516 | call unset_derivs_params() |
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| 517 | |
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| 518 | call pop_sub() |
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| 519 | end subroutine inward_integration |
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| 520 | |
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| 521 | function practical_infinity(e, wave_eq, tol) |
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| 522 | !-----------------------------------------------------------------------! |
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| 523 | ! Returns the value of the practical infinity. The practical infinity ! |
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| 524 | ! is such that wavefunction at the practical infinity is of the order ! |
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| 525 | ! of magnitude of SCHRODINGER_FINF or DIRAC_FINF. ! |
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| 526 | ! ! |
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| 527 | ! e - energy ! |
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| 528 | ! wave_eq - wave-equation to use ! |
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| 529 | ! tol - tolerance ! |
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| 530 | !-----------------------------------------------------------------------! |
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| 531 | real(R8), intent(in) :: e |
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| 532 | integer, intent(in) :: wave_eq |
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| 533 | real(R8), intent(in) :: tol |
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| 534 | real(R8) :: practical_infinity |
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| 535 | |
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| 536 | real(R8) :: k, x, f, xm, d |
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| 537 | |
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| 538 | call push_sub("practical_infinity") |
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| 539 | |
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| 540 | select case (wave_eq) |
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| 541 | case (SCHRODINGER) |
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| 542 | if (e == M_ZERO) then |
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| 543 | practical_infinity = -log(SCHRODINGER_FINF)/sqrt(M_TWO*1.0e-12) |
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| 544 | else |
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| 545 | practical_infinity = -log(SCHRODINGER_FINF)/sqrt(-M_TWO*e) |
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| 546 | end if |
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| 547 | case (DIRAC) |
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| 548 | k = sqrt(-e)*sqrt(M_TWO + e/M_C2) |
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| 549 | x = M_ZERO |
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| 550 | f = -M_HALF*log(x) - k*x - log(DIRAC_FINF) |
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| 551 | d = -log(DIRAC_FINF)/k - x |
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| 552 | do |
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| 553 | d = d*M_HALF |
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| 554 | xm = x + d |
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| 555 | if (f*(-M_HALF*log(xm) - k*xm - log(DIRAC_FINF)) > M_ZERO) x = xm |
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| 556 | if (-M_HALF*log(xm) - k*xm - log(DIRAC_FINF) == M_ZERO .or. d <= tol) exit |
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| 557 | end do |
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| 558 | practical_infinity = xm |
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| 559 | case (SCALAR_REL) |
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| 560 | if (e == M_ZERO) then |
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| 561 | practical_infinity = -log(SCHRODINGER_FINF)/sqrt(M_TWO*(M_ONE - 1.0e-12/M_TWO/M_C**2)*1.0e-12) |
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| 562 | else |
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| 563 | practical_infinity = -log(SCHRODINGER_FINF)/sqrt(-M_TWO*(M_ONE + e/M_TWO/M_C**2)*e) |
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| 564 | end if |
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| 565 | |
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| 566 | end select |
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| 567 | |
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| 568 | call pop_sub() |
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| 569 | end function practical_infinity |
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| 570 | |
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| 571 | subroutine wave_equations_integrator_debug(integrator, ri, rf, nstep, r, g, f) |
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| 572 | !-----------------------------------------------------------------------! |
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| 573 | ! Prints debug information to the "debug_info/integrator" file. ! |
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| 574 | ! ! |
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| 575 | ! integrator - integrator object ! |
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| 576 | ! ri - initial integration point ! |
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| 577 | ! rf - final integration point ! |
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| 578 | ! nstep - number of steps taken by the solver ! |
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| 579 | ! r - mesh used by the ODE solver ! |
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| 580 | ! g - wavefunction ! |
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| 581 | ! f - wavefunction ! |
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| 582 | !-----------------------------------------------------------------------! |
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| 583 | type(integrator_t), intent(in) :: integrator |
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| 584 | real(R8), intent(in) :: ri, rf |
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| 585 | integer, intent(in) :: nstep |
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| 586 | real(R8), intent(in) :: r(integrator%nstepmax), g(integrator%nstepmax), f(integrator%nstepmax) |
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| 587 | |
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| 588 | integer :: unit, i |
|---|
| 589 | |
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| 590 | call push_sub("wave_equations_integrator_debug") |
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| 591 | |
|---|
| 592 | call io_open(unit, file='debug_info/integrator') |
|---|
| 593 | write(unit,'("ODE Integrator tolerance: ",ES10.3E2)') integrator%tol |
|---|
| 594 | write(unit,'("ODE Integrator maximum number of steps: ",I6)') integrator%nstepmax |
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| 595 | write(unit,'("ODE Integrator minimum step size: ",ES10.3E2)') integrator%hmin |
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| 596 | close(unit) |
|---|
| 597 | |
|---|
| 598 | call io_open(unit, file='debug_info/wavefunctions') |
|---|
| 599 | write(unit,'("# Integration Starting Point: ",ES10.3E2)') ri |
|---|
| 600 | write(unit,'("# Integration Ending Point: ",ES10.3E2)') rf |
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| 601 | do i = 1, nstep |
|---|
| 602 | write(unit,'(ES10.3E2,1X,ES10.3E2,1X,ES10.3E2)') r(i), g(i), f(i) |
|---|
| 603 | end do |
|---|
| 604 | close(unit) |
|---|
| 605 | |
|---|
| 606 | call pop_sub() |
|---|
| 607 | end subroutine wave_equations_integrator_debug |
|---|
| 608 | |
|---|
| 609 | subroutine wave_equations_integrator_end(integrator_sp, integrator_dp) |
|---|
| 610 | !-----------------------------------------------------------------------! |
|---|
| 611 | ! Frees all the memory associated with the GSL objects used by the ! |
|---|
| 612 | ! ODE solver. ! |
|---|
| 613 | !-----------------------------------------------------------------------! |
|---|
| 614 | type(integrator_t), intent(inout) :: integrator_sp, integrator_dp |
|---|
| 615 | |
|---|
| 616 | call push_sub("wave_equations_integrator_end") |
|---|
| 617 | |
|---|
| 618 | !Free GSL objects for simple precision integrations |
|---|
| 619 | call gsl_odeiv_step_free(integrator_sp%stp) |
|---|
| 620 | call gsl_odeiv_evolve_free(integrator_sp%evl) |
|---|
| 621 | call gsl_odeiv_control_free(integrator_sp%ctrl) |
|---|
| 622 | |
|---|
| 623 | !Free GSL objects for double precision integrations |
|---|
| 624 | call gsl_odeiv_step_free(integrator_dp%stp) |
|---|
| 625 | call gsl_odeiv_evolve_free(integrator_dp%evl) |
|---|
| 626 | call gsl_odeiv_control_free(integrator_dp%ctrl) |
|---|
| 627 | |
|---|
| 628 | call pop_sub() |
|---|
| 629 | end subroutine wave_equations_integrator_end |
|---|
| 630 | |
|---|
| 631 | end module wave_equations_integrator_m |
|---|