Firefly and PC GAMESS-related discussion club


 
Learn how to ask questions correctly  
 
 
We are NATO-free zone
 



Re^2: Excited-state geometry optimization with numerical gradients

Dawid
dawid.grabarek@pwr.edu.pl


Dear Professor Granovsky,

Thank you for clarifying that. I got confused after reading the
manual which says that

"Then, three other important keywords should be mentioned. The NGRADS keyword can be used
to request gradients for multiple states of interest, when using a method that can calculate the
energies of several states at once (such as MCSCF). The default is NGRADS=1, meaning that the
gradient is only computed for the lowest energy state. NGRADS=3, for example, will calculate the
gradients of the three lowest states. Obviously, the amount of states requested with NGRADS
should not be larger than the amount of states available."

as well as for ISTATE

"This option selects the target state of interest, i.e. the state which’ gradient is to
be used by other parts of the program, for example during geometry optimization
involving numerical gradients. This option is intended for use together with the
NGRADS option. For instance, to optimize the second root of TDDFT or XMCQDPT,
set NGRADS equal to or greater than 2, set ISTATE to 2, and properly set other
relevant parameters controlling the number of computed roots during TDDFT or
XMCQDPT procedure to capture at least two states. (Default is 1)
"

So I figured out that even though I use ISTATE in $XMCQDPT I
still need it properly set in $NUMGRD.

Best regards,
Dawid Grabarek

On Wed Jan 4 '17 10:42pm, Alex Granovsky wrote
----------------------------------------------
>Dear Dawid,

>

 $XMCQDPT2 istate=2 $END 

>is the valid way to specify that you requests optimization of a second root.
>This can be done differently (using $numgrd input) but this is not necessary.

>Kind regards,
>Alex Granovsky
>
>
>
>On Wed Jan 4 '17 8:26pm, Dawid wrote
>------------------------------------
>>Dear All,

>>What does actually happen if I specify XMC-QDPT2 geometry optimization
>>calculations in the first excited state (istate=2) with 2-SA-CASSCF
>>reference but I don't use

>>$NUMGRD
>> ngrads=2
>> istate=2
>>$END

>>?
>>Does it mean that the geometry in the first excited state is
>>calculated based on the ground electronic state gradient?

>>Best regards,
>>Dawid


[ Previous ] [ Next ] [ Index ]           Wed Jan 4 '17 11:21pm
[ Reply ] [ Edit ] [ Delete ]           This message read 232 times