Usage:
% dp [-i inputfile] [-g gwfile] [-k] kssfile

inputfile is a parsed file. 
comments can be included through the # character.
you can use some keywords:
testparticle / testelectron       # choose testparticle
rpa / lda / gw / so / gw+a / so+a # fxc kernel option
                                  # gw = gw corrections
                                  # so = scissor operator
				  # a = alpha/q^2 kernel
				  
npwmat 25                         # dimension of the dielectric matrix 
npwwfn 69                         # dimension of the basis for the expansion 
                                  # of the wavefunction
nbands 9                          # highest band included in sums over states
soenergy 0.8                      # scissor operator
omegai 0.0                        # initial energy
omegae 9.0                        # final energy
domega 0.1                        # energy step
alpha -0.2                        # value of the parameter alpha     

some others have a reasonable default:
broad   (default to domega)       # broadening of the spectrum
q 0.0 0.0 0.0                     # vector q of the incoming light or electrons  
lomo 2                            # lowest band included in sums over states



plus some others which are read anyway from kss file
nkibz 2                           # number of k points
nsym 24                           # number of symmetry operations
noinv                             # no inversion
nel 8                             # number of electrons


CPU, memory usage:

The calculation fo chi^(0) scales as: 
npwmat^2 * ~nbands * nkbz * nr log nr
where nr is the real space mesh calculated from npwwfn.

The calculation of epsilon_M from chi^(0) in RPA scales as:
<npwmat^2 * nomega

The occupied memory is about:
(npwmat^2 * nomega + nr * nkibz * nbands ) * sizeofcomplex