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Re^4: CASSCF and basis set extrapolation

Dobromir Antonov Kalchevski
dobromirak@gmail.com


Yes, of course.

I'm attaching 5 input files for steps: single point S0 (for orbitals), S0 opt, S1 opt, conical intersection search, scan. It's a research in progress, so I don't want to upload the exact molecule. Yet without it I know it may be hard to optimize the options. It's a conjugated system with C1 symmetry, and I am studying it's E/Z isomerization, after photo-excitation. I think I can rely on sto-3g at least as far as not excluding a barrier of rotation, when the molecule is going through isomerization by it's S1 PES ? Or not finding a barrier, when there is none ? The exact size of the barrier is not of importance.

Thank you in advance,
Best regards,
Dobromir

On Mon Apr 20 '15 6:54am, sanya wrote
-------------------------------------
>>I am searching for qualitative results more than for quantitative ones. Can I expect good state-averaged optimizations, PE Scans, and conical intersection results from STO-3G basis and MCSCF ? Meaning no missing or extra intermediates / transition states on a excited state (S1) potential energy surface, regarding a reaction path coordinate ?

>I'm afraid the basis set missing polarization functions may give qualitatively wrong results. Actually, your molecule is not too big, you may safely use 6-31G(d,p).

>>As amazed as I am with the speed of Firefly 8.1.0, my resources (including time) at the moment are limited. I hope these new questions are not an off-topic.

>Can you show us you input file? Probably, I or Alex can suggest some improvements to speed up your calculations and save memory and/or disk.

This message contains the 3 kb attachment
[ sending.rar ] input setup

[ This message was edited on Tue Apr 21 '15 at 3:46pm by the author ]


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