If =0 the propagation of the solvent polarization charges starts from internally generated initial charges
in equilibrium with the initial potential.
For Debye EOM-PCM, if >0 the propagation of the solvent polarization charges starts from initial charges from input file.
if =1, initial pol. charges due to solute electrons are read from input file.
else if =2, initial pol. charges due to external potential are read from input file.
else if =3, initial pol. charges due to solute electrons and external potential are read from input file.
Files should be located in pcm directory and are called ASC_e.dat and ASC_ext.dat, respectively.
The latter files are generated after any PCM run and contain the last values of the polarization charges.