Firefly and PC GAMESS-related discussion club

 
Learn how to ask questions correctly  
 
 

 

Alex Granovsky
gran@classic.chem.msu.su

Do you need relaxed or expectation-value dipole moments?

Relaxed dipole moments could be computed using the same
approach as the one used by SA-CASSCF gradient code, namely,
by differentiation of state-averaged dipole moment
with respect to a state weight. This is because the differentiation
of averaged one and two particle density matrices with respect to
a state weight produces response-type state-specific density
matrices. This is the most general and powerful statement related
to such a differentiation which allows computation of state-specific
gradients and any one and two-electron properties using such
differentiation.

If you can wait a month or so, the code for relaxed dipole moments
will be available as a part of Firefly.

Computation of expectation-value state-specific dipole moments is
even simpler. The dipole moments of this type can be computed
by the present code. If this is the type of dipole moments you need,
please let me know and I'll post sample input file.

Kind regards,
Alex Granovsky


On Wed Mar 27 '13 7:05pm, Matthieu Sala wrote
---------------------------------------------
>Dear Firefly users,

>I would like to know if there is a way to compute excited state dipole moments from a state averaged CASSCF calculation in Firefly.

>The reason is that I would like to compute excited state polarizabilities by finite differentiation of the dipole rather than double differentiation of the energy with respect to an applied field.

>I know that I can obtain zero order QDPT dipole moments from a XMCQDPT2 calculation and that these might be better than CASSCF although not of full XMCQDPT2 quality. However I would like to compute pure CASSCF dipole moments, at least for the purpose of comparison.

>Best regards.
>Matthieu Sala