PC GAMESS-related discussion club

Re^2: TDDFT/TDA_restarts

Richard
bonarlaw@liv.ac.uk

Thanks Alex, this might be a useful feature for large molecules, since if I understand it right, these are all-or-nothing calculations i.e. one can't just ask for the high energy states alone.

A related problem: have you any suggestions for when the Davidson iterations show no sign of converging even when using more accurate DFT ? (I used the settings suggested in the May 14 '07 post)

Thanks

Richard



On Sun May 11 '08, Alex Granovsky wrote
---------------------------------------
>Dear Richard,

>while it is impossible at present (just because this is not
>programmed), there should not be any serious problems with
>implementation of this feature. At present, old CIS/TD vectors
>are only used as a starting guess for the subsequent calculations
>at the distorted geometries (e.g., geometry optimization).

>Best regards,
>Alex
>
>
>
>On Fri May 9 '08, Richard wrote
>-------------------------------
>>I don't pretend to understand how these calculations work, but....having run a TDDFT/TDA job with a particular value of NSTATE, should it be possible to rerun the job with a larger value for NSTATE, making use of the already calculated data so the first set of states don't have to be redone i.e. just carry on? It seems the program expects the number of states in the TDVEC group to match NSTATE.

>>thanks

>>Richard

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