## Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly

** 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

Wed Jan 4 '17 11:21pm

This message read **232** times