# [Octopus-users] Time dependent DFT run problem

Jessica Mecier jessica.mecier at gmail.com
Mon Aug 18 15:22:49 WEST 2008

```Dear all,

I am having the following headaches problems.

1- Acceleration
I found that if I use the key work acceleration (to compute the harmonic
spectrum) in the TDOUTPUT, the program doesn't work (breaks) and there is
any error message, Why? (an input file example is supplied below, the
program works if  acceleration is removed. Note that I had the same problem
with the different input of the tutorial manual)

2- Is it a way to get the total density in my box (grid) at the end of my
TDDFT run?

3- does someone have any experience with the oct-harmonic-spectrum utility?
my spectra looks always strange (not clear difference between odd and pair
number. even for the case of He where the experimental spectrum is well
known, I did not get a good graph)

I am looking forward to hear from some one soon.

Jessica,
Montreal, UDM

****************************inp****************************
CalculationMode = td
Unitsinput = atomic
spacing = 0.30

CH = 2.3
%Coordinates
"C" |           0 |          0 |           0 | no
"H" |  CH/sqrt(3) | CH/sqrt(3) |  CH/sqrt(3) | no
"H" | -CH/sqrt(3) |-CH/sqrt(3) |  CH/sqrt(3) | no
"H" |  CH/sqrt(3) |-CH/sqrt(3) | -CH/sqrt(3) | no
"H" | -CH/sqrt(3) | CH/sqrt(3) | -CH/sqrt(3) | no
%
ParallelizationStrategy = par_domains

#######LASER######
TDEvolutionMethod = aetrs
TDMaximumIter = 12000
TDTimeStep = 0.03
amplitude = 0.292577677
omega = 0.0584
tau0 = 330/2
t0 = 330/2+15
%TDExternalFields
electric_field | 0 | 0 | 1 | envelope_cosinusoidal | amplitude | omega |
tau0 | t0
%

TDprojstatestart = 3
OutputEvery=1000
Output = wfs + density + elf + potential +ksdipole + pol_density
TDOutput = multipoles + td_occup + populations  + acceleration
OutputHow = gnuplot + plane_x + plane_z

#### Spectrum analysis####
Hspolarization = 'z'
SpecMaxenergy = 300 # or30
*********************************end inp***********************
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