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Re: Output of the gradients during CI optimization

Alex Granovsky
gran@classic.chem.msu.su


Hi Julia,

>1) I assume that firefly needs the gradients of the states involved in the CI search in order to build the penalty function gradient. Is there any possibility to output these gradients?

Are you interested in gradients for SA-MCSCF?

You can find documented here:

http://classic.chem.msu.su/gran/gamess/readme.html

In particular:

http://classic.chem.msu.su/gran/gamess/ss-gradients.html

For SA-MCSCF, you just need to provide istate and jstate and run runtyp=gradient run.

>2) My CI optimization is converging to a minimum in the intersection space but the degeneracy is not as small as I would like. Is there any possibility to run an optimization of the energy difference only?

You can use Lagrange multiplier based optimization
(see http://classic.chem.msu.su/gran/gamess/Locating_Conical_Intersections_and_Interstate_Crossings_with_Firefly.html for details).
Alternatively, you can provide non-default value of parameters of
a penalty function to make it more sensitive to energy difference.

Hope this helps.

Kind regards,
Alex Granovsky


On Mon May 27 '13 10:31pm, Julia Endicott wrote
-----------------------------------------------
>I have two questions related to conical intersection (CI) optimizations.

>1) I assume that firefly needs the gradients of the states involved in the CI search in order to build the penalty function gradient. Is there any possibility to output these gradients?

>2) My CI optimization is converging to a minimum in the intersection space but the degeneracy is not as small as I would like. Is there any possibility to run an optimization of the energy difference only?

>Thank you in advance,

>Julia


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