As it concerns time-dependent electric and magnetic molecular property densities, the IC package provides the TD2PT program to convert the *.chk file, from a time-dependent G16 calculation (TD-HF or TD-DFT), to the standard files used by the IC package for the calculation and visualization of the property densities as described in the previous sections. Mandatory is to run the command:
Ψprompt> chk2fbas g16-chk-file-name
before using TD2PT, where g16-chk-file-name is the G16 chk file name provided within the gjf or com input file, without typing the chk extension. The command produces the *.bas and *.fchk used by the TD2PT program, see the following.
A list of available options can be obtained typing
Ψprompt> TD2PT -h ****************************** * TD2PT - mm dd, yyy - hh:mm * ****************************** Usage: TD2PT command_line_arguments. The first mandatory argument is the base_file_name of two files of type *.baf and *.fchk/fch, used by TD2PT to generate perturbed MO coefficients. Of course, *.baf and *.fchk/fch files must exist in in the current folder. These can be obtained from a Gaussian *.chk file as: >formchk -mat -i4labs -files="(635)" *.chk *.baf >formchk *.chk When *.chk contains Excited state and G to E trans densities, a smaller copy can be obtained using: >copychk 0 *.chk *_nodens.chk not 633 The shorter *_nodens.chk can be used in the above formchk commands. Other optional command line arguments are: -w #E: radiation energy E in au -eV #omega: radiation frequency omega in eV -nm #lambda: radiation frequency lambda in nm -H off-diagonal HV relations -u n: use n exc_states to compute the perturbed coefficients -p n: print n exc_states data values -v verbose printing -nch check if ST+=TS+=1 -d dump fchk (use with attention, sice it produces a large output) -bcp MOLGRA_output_file_name -h help
In order to integrate property densities using the atomic size adjustments based on the bond critical points (BCP) of the electron density, see MOLGRA in section 4.4, the -bcp option is required .