PC GAMESS/Firefly-related discussion club

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Alex Granovsky
gran@classic.chem.msu.su

note there are some differences in syntax of $cis group
between  GAMESS (US) and PC GAMESS/Firefly, e.g., nacore vs. ncore, istate vs. iroot, etc...

Regards,
Alex Granovsky

On Mon Dec 8 '08 7:36pm, Jaden Curtis wrote
-------------------------------------------
>Sure.  The purpose of the calculation itself is just to gain a deeper understanding of how PC GAMESS works.  Specifically, it is to find the first excited state of formaldehyde (CIS level of theory) using the optimized ground stae geometry.  The input is as follows...

> $contrl  scftyp=rhf runtyp=gradient coord=zmt cityp=cis
>     icharg=0 mult=1 $end
> $basis  gbasis=n31  ngauss=6 ndfunc=1 nffunc=1 $end
> $cis hamtyp=saps mult=1 nacore=0 nstate=1 iroot=1 $end
> $data
>formaldahyde with 6-31+g*
>Cnv 2

>O
>C   1   1.179524
>H   2   1.0932719   1  122.289034  
>H   2   1.0932719   1  122.289034  3  180.0
> $end
>
>
>Then I would like to relax the geometry of formaldehyde in this excited state (the first excited state according to CIS).  This is where I'm experiencing difficulty.  I cannot determine how to tell the program to keep the molecule in the first excited state and perform a geometric optimization in the first excited state.  It simply falls back down to the ground state.  I understand that the energy gradients for the excited state along with a few other properties are punched into the .dat file.  What I need to determine is the procedure for using this information in the calculation to relax the excited state geometry of the molecule.  Information such as, what runtype command should be used for this type of calculation, would also be helpful.  I have seen many example calculation for GAMESS, but none seem to handle this particular procedure.  Thanks again for your time and help.
>  
>
>
>
>On Sat Dec 6 '08 9:29pm, Alex Granovsky wrote
>---------------------------------------------
>>Hi,

>>could you be a little bit more specific?

>>Regards,
>>Alex Granovsky
>>
>>
>>On Sat Dec 6 '08 3:45am, Jaden Curtis wrote
>>-------------------------------------------
>>>I am aware of the need for the gradients of the particular state you wish to probe.  It's the next step that seems to be giving me the trouble.

[ This message was edited on Mon Dec 22 '08 at 10:10am by the author ]