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Re^8: CIS optimization state energy moves unreasonably

Alex Granovsky
gran@classic.chem.msu.su


Hi Jonas,

to allow state-specific gradients for state-averaged MCSCF,
you need to add several additional keywords. See e.g.
the following thread for details:

http://classic.chem.msu.su/cgi-bin/ceilidh.exe/gran/gamess/forum/?C3dcd10513NCe-6895-334-00.htm

and search forum for additional information on this.

Regards,
Alex Granovsky


On Sun Aug 1 '10 5:50pm, Jonas Baltrusaitis wrote
-------------------------------------------------
>Well, tried optimization off converged MCSCF guess, turns out I can't average?.. That's weird

> **** ERROR, RUNTYP=OPTIMIZE REQUIRES ENERGY GRADIENT.
> THIS IS IMPOSSIBLE WHILE STATE AVERAGING. NAVG=    5

>Should I just ask for a brightest state gradient? Also, activate tracking of all states? It's 4 excited states I am working with, so would this work?

>$MCSCF ISTATE=5 ntrack=5

>Would this optimize to 4th excited state and track all 5 states (ground+4 excited)? Is there any value of state tracking in state averaged calculations?

>Jonas

>On Sat Jul 31 '10 1:56am, Jim Kress wrote
>-----------------------------------------
>>NBOs and NOs are not the same.  In addition, the NBO analysis will specifically decomopose the NBO orbitals according to nuclear center, bonding type, and AO contribution.

>>Look here for more info:

>>http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/http://www.chem.wisc.edu/~nbo5/

>>Jim

>>On Thu Jul 29 '10 4:49am, Jonas Baltrusaitis wrote
>>--------------------------------------------------
>>>I got similar suggestion from Sanya only he suggested natural orbitals of interest.

>>>Maybe I am not interpreting right: all I need is emission spectrum. So I do not have particular bonds or orbitals in mind, I only need to optimize to certain excited state or averaged states to get decent representation of fluorescence spectra. Does that change anything or I still have to select bond or orbital wise?

>>>Also, would that make these calculations state specific or state average?

>>>Jonas
>>>
>>>
>>>On Wed Jul 28 '10 6:35pm, Jim Kress wrote
>>>-----------------------------------------
>>>>Try doing a NBO analysis.  Then select your active space from the set of NBOs (or even NLMOs) that correspond to the atoms and/or bonds of primary concern to you.

>>>>This is how I usually set-up my MCSCF/ CASSCF calculations.

>>>>Jim

>>>>On Wed Jul 28 '10 3:15am, sanya wrote
>>>>-------------------------------------
>>>>>On Tue Jul 27 '10 4:16pm, Jonas Baltrusaitis wrote
>>>>>--------------------------------------------------
>>>>>>From what I've read in the literature CASSCF should be a good thing for my molecules since it can deal with multireference character and bond breaking. I am a bit hesitant since I am not sure how to select the active space. Would TDDFT do in selecting which orbitals and electrons to correlate? Is there a rule of thumb?

>>>>>DFT (as well as HF) orbitals are not very good as starting MOs. Natural orbitals are better. Unfortunately, there is no rule of thumb in selecting the active space, just a common sense and a chemical insight :) In fact, it is individual for each molecular system.


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