Siddheshwar Chopra
sidhusai@gmail.com
Regards,
On Tue Mar 4 '14 11:41am, Thomas Pijper wrote
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>Dear Siddheshwar,
>A few comments:
>$SCF NCONV=8 is very tight, I'd say that the default NCONV=5 would be sufficient in your case.
>$TDDFT NSTATE=100 is a lot of states. I expect that 30 to 40 states is enough if you are trying to obtain a UV/vis spectrum. This should speed up your calculation significantly.
>$CONTRL INTTYP=HONDO ICUT=11 ITOL=30 should not be necessary (unless you are calculating a numerical gradient). Same goes for $DFT LMAX=41 NRAD=99. This will help in speeding up your calculation.
>$BASIS GBASIS=N31 NGAUSS=6 is a very light basis set. I would at least try to add NDFUNC=1 (resulting in the 6-31G(d) basis).
>
>
>Kind regards,
>Thom
>
>
>
>On Tue Mar 4 '14 10:07am, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear Sir,
>>Thank you for pointing out this silly mistake of mine. I will note this down now. As for the TDDFT calculations please find attached the i/p file. I have used the lowest energy state coordinates for the same. Please have a look at it.
>>Regards,
>>On Mon Mar 3 '14 5:51pm, Thomas Pijper wrote
>>--------------------------------------------
>>>Dear Siddheshwar,
>>>> I ran HEssian calculations on my sample first. I
>>>> got NO imaginary frequencies. But I could not find
>>>> "Equilibrium geometry located" text anywhere.
>>>This is because you specified RUNTYP=HESSIAN. This performs a Hessian calculation. The message "Equilibrium geometry located" appears only with a completed geometry optimization (RUNTYP=OPTIMIZE or SADPOINT). Your geometry does correspond to a minimum on the PES.
>>>
>>>
>>>> I run TDDFT calcs. But in that I am getting this error now:
>>>>
>>>> * ... LESS THAN �3.000
>>>>
>>>> **** THERE ARE ATOMS LESS THAN � 0.100 APART, QUITTING... ****
>>>
>>>
>>>Most likely you made an error in the $DATA group of the TDDFT calculation input. It could for example be that you specified a point group other than C1, but specified coordinates corresponding to the C1 geometry, thus causing some atoms to be specified twice. If you would like me to take a closer look at the problem, feel free to post the input file for your TDDFT calculation.
>>>
>>>
>>>Kind regards,
>>>Thom
>>>
>>>
>>>
>>>
>>>
>>>On Mon Mar 3 '14 11:21am, Siddheshwar Chopra wrote
>>>--------------------------------------------------
>>>>Dear Sir,
>>>>I ran HEssian calculations on my sample first. I got NO imaginary frequencies. But I could not find "Equilibrium geometry located" text anywhere. Now thinking that it is a global minimum, I run TDDFT calcs. But in that I am getting this error now:
>>>> �* ... LESS THAN �3.000
>>>> **** THERE ARE ATOMS LESS THAN � 0.100 APART, QUITTING... ****
>>>>What is wrong here? What should I do next to rectify this. If the sample was not in global minima, then how come there were no imaginary freqs?
>>>>Regards,