Potential energy curve of excited states of Ne dimer

Hi everyone, as a beginner, I am having some doubts about implementing psi4 to calculate potential energy curve.
As an example, I take Ne dimer from available code.

memory 250 mb

molecule dimer {

Ne 1 R


set basis aug-cc-pVDZ
set freeze_core True

Initialize a blank dictionary of counterpoise corrected energies

(Need this for the syntax below to work)

ecp = {}

for R in Rvals:
dimer.R = R
ecp[R] = energy(‘ccsd(t)’, bsse_type = ‘cp’)

for R in Rvals:
e = ecp[R] * psi_hartree2kcalmol
psi4.print_out(" %3.1f %10.6f\n" % (R, e))

After compiling this code, I got energy for different R.

1.2 -161172.863392
1.4 -161389.785298
1.6 -161476.641746
1.8 -161510.881951
2.0 -161524.254853
2.2 -161529.495203
2.4 -161531.575114
2.6 -161532.357984
2.8 -161532.621035
3.0 -161532.703421
3.2 -161532.722818
3.4 -161532.715479
3.6 -161532.698071
3.8 -161532.679608
I got a curve which corresponds to ground state.

But I do not know how to find pec for other electronic excited states. Any suggestion would be helpful.

Have you looked for any samples of EOM-CCSD inputs among the Psi samples? That would be the excited state analogue of CCSD.

Psi also has TD-DFT for the upcoming 1.4 release, but using that now would require you to have a non-release version of Psi.