Alex Granovsky
gran@classic.chem.msu.su
you should distinguish program errors (there are none at present
in the Firefly's DFT/TDDFT code) and errors due to use of simplified
and inaccurate model (like TDDFT is).
>>2. As to second part of your question, could you please be a bit
>>more specific. It is hard to answer without looking into actual
>>output files. Note, in C2 group, there are no forbidden transitions
>>at all. Does your question mean that you got large transition
>>moments for forbidden transitions in Ci group?
>I did not get large transition moments for forbidden transitions in Ci group.
Small non-zero transition moments for forbidden transitions are
usually due to numerical noise/use of finite grid used in DFT/TDDFT
calculations. Use larger grid or explicit symmetry in TDDFT.
Kind regards,
Alex Granovsky