I’m trying to get excited states and the transition dipole moment using TD-DFT
Here’s an example of what I am doing:
molecule mol {
0 1
O 0.00000000 0.00000000 0.00000000
H -0.75725300 -0.00000000 -0.58843500
H 0.75725300 0.00000000 -0.58843500
}
set scf_type df
set reference rks
set s_tolerance 1e-9
from psi4.driver.procrouting.response.scf_response import tdscf_excitations
e, wfn = energy('b3lyp-d3bj/aug-cc-pVTZ', return_wfn=True)
res = tdscf_excitations(wfn, states=8)
mol.print_out()
print_variables()
The key output is then:
TDSCF excitation energies
by Andrew M. James and Daniel G. A. Smith
---------------------------------------------------------
********************************************************************************
********** WARNING **********
********** TDSCF is experimental results may be inaccurate **********
********************************************************************************
==> Requested Excitations <==
0 states with A1 symmetry
0 states with A2 symmetry
0 states with B1 symmetry
0 states with B2 symmetry
==> Options <==
etol : 1e-06
rtol : 1e-08
guess_type: denominators
restricted: True
triplet : False
ptype : rpa
Final Energetic Summary:
Excitation Energy Total Energy
# Sym: GS->ES (Trans) [au] [eV] (au)
In other words, no result is found.
The similar calculation with EOM-CC2 as:
0 1
O 0.00000000 0.00000000 0.00000000
H -0.75725300 -0.00000000 -0.58843500
H 0.75725300 0.00000000 -0.58843500
}
set scf_type pk
set basis aug-cc-pVTZ
set reference rhf
e, wfn = energy('cc2', return_wfn=True)
set roots_per_irrep [0, 0, 2, 2]
properties('eom-cc2', properties=['oscillator_strength'])
mol.print_out()
print_variables()
Gives ‘desirable’ results, for example:
Ground State -> Excited State Transitions
Excitation Energy OS RS RS Einstein A
State (eV) (cm^-1) (nm) (au) (l,au) (v,au) (s^-1)
1 B1 11.207 90389.9 110.6 0.411847 0.0142 0.0000 0.0000 7.731354E+07
2 B1 13.017 104987.9 95.2 0.478360 0.0832 0.0000 0.0000 6.116557E+08
1 B2 7.244 58424.9 171.2 0.266203 0.0578 0.0000 0.0000 1.316965E+08
2 B2 10.376 83686.2 119.5 0.381302 0.0006 0.0000 0.0000 2.774351E+06
Doing transition
*********************************************************************
*********************************************************************
************ ************
************ Excited State-Excited State Transition Data ************
************ ************
*********************************************************************
*********************************************************************
*** Computing <1B1|X{pq}}|2B1> (LEFT) Transition Density ***
*** LTD Setup complete.
***...density has been built...
***...density has been sorted...
*** Computing <2B1|X{pq}}|1B1> (RIGHT) Transition Density ***
*** RTD Setup complete.
***...density has been built...
***...density has been sorted...
What needs to be different in the TD-DFT setup to get the transitions and corresponding transition dipole moments?
thanks!