Author Topic: Permanent dipole moment excited states  (Read 4215 times)

dpleft

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Permanent dipole moment excited states
« on: June 24, 2023, 11:29:48 PM »
Hello all,
I a doing a TD-DFT calculation and I am interested in the excited states dipole moments. I am interested in the permanent dipole moments of the excited states. I have been able to find only the permanent dipole moment of the ground state.

This is my control file,
Code: [Select]
$lastdiag
$rpacor    400
$maxcor    500 MiB  per_core
$dft
 functional cam-b3lyp
 gridsize m4
$soes all    1
$cdspectrum    nm
$spectrum    nm
$subtitle
SP,DFT/no-RI,CAM-B3LYP,charge -1,cs,aug-cc-pVDZ,EX_STATE_VERTICAL_EXCITATION
$scfiterlimit    100
$coord    file=coord
$scfconv    6
$grad    file=gradient
$scfinstab    rpas
$optimize
 internal off
 redundant off
 cartesian on
 global off
$symmetry    cs
$tmole
$basis    file=basis
$scfmo   file=mos
$atoms
o 13-14 \
   basis = o aug-cc-pVDZ
n 3,5 \
   basis = n aug-cc-pVDZ
h 15-21 \
   basis = h aug-cc-pVDZ
c 1-2,4,6-12 \
   basis = c aug-cc-pVDZ
$scfdamp     start=0.700 step=0.050 min=0.100
$operating system    unix
$closed shells
 a'      1-41                                   ( 2 )
 a"      1-8                                    ( 2 )
$scfdump
$scfdiis
$scforbitalshift  automatic=.1
$energy    file=energy
$rundimensions
   natoms=21
$end
Is there a keyword to provide so that I am about to get the permanent dipole moments of the excited states? Or where can I locate it in the manual.

Thank you

chris.hol

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Re: Permanent dipole moment excited states
« Reply #1 on: June 25, 2023, 06:28:48 PM »
Hi dpleft,

excited state dipole moments can be calculated using egrad. They are a "byproduct" of the excited state gradient (sharing some terms with them indeed). To obtain the dipole moment of the first excited state, modify your control file accordingly by adding $exopt 1, and then run egrad:

Code: [Select]
$lastdiag
$rpacor    400
$maxcor    500 MiB  per_core
$dft
 functional cam-b3lyp
 gridsize m4
$soes all    1
$exopt 1
$rij
$cdspectrum    nm
$spectrum    nm
$subtitle
SP,DFT/no-RI,CAM-B3LYP,charge -1,cs,aug-cc-pVDZ,EX_STATE_VERTICAL_EXCITATION
$scfiterlimit    100
$coord    file=coord
$scfconv    6
$grad    file=gradient
$scfinstab    rpas
$optimize
 internal off
 redundant off
 cartesian on
 global off
$symmetry    cs
$tmole
$basis    file=basis
$scfmo   file=mos
$atoms
o 13-14 \
   basis = o aug-cc-pVDZ
n 3,5 \
   basis = n aug-cc-pVDZ
h 15-21 \
   basis = h aug-cc-pVDZ
c 1-2,4,6-12 \
   basis = c aug-cc-pVDZ
$scfdamp     start=0.700 step=0.050 min=0.100
$operating system    unix
$closed shells
 a'      1-41                                   ( 2 )
 a"      1-8                                    ( 2 )
$scfdump
$scfdiis
$scforbitalshift  automatic=.1
$energy    file=energy
$rundimensions
   natoms=21
$end

Note that range-separated hybrids like CAM-B3LYP require the RI approximation in egrad, so I also added the $rij keyword. In the end of the calculation, the excited state dipole moment should then be reported in a very similar manner as for the ground state.

Best,
Christof

dpleft

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Re: Permanent dipole moment excited states
« Reply #2 on: June 27, 2023, 06:49:43 PM »
This is helpful, thank you for the reply!