Hello everyone,
I am having difficulty defining different frozen core settings in a composite scheme. My objective is to correlate all electrons at the MP2/CBS level while, for CCSD(T), I want to correlate only the valence electrons. I would like to know if it is possible to achieve this in Psi4.
Here is the input that I am using:
molecule h2o {
O
H 1 0.95
H 1 0.95 2 104.4
}
set {
scf_type direct
mp2_type conv
cc_type conv
e_convergence 7
reference rhf
freeze_core true
}
def test_composite(**kwargs):
scf = {
'wfn': 'hf',
'basis': kwargs.pop('scf_basis', 'aug-cc-pwCV[TQ]Z'),
'scheme': kwargs.pop('scf_scheme', 'scf_xtpl_helgaker_2')
}
corl = {
'wfn': kwargs.pop('corl_wfn', 'mp2'),
'basis': kwargs.pop('corl_basis', 'aug-cc-pwCV[TQ]Z'),
'scheme': kwargs.pop('corl_scheme', 'corl_xtpl_helgaker_2')
}
delta = {
'wfn': kwargs.pop('delta_wfn', 'ccsd(t)'),
'wfn_lesser': kwargs.pop('delta_wfn_lesser', 'mp2'),
'basis': kwargs.pop('delta_basis', 'def2-SVP'),
'scheme': kwargs.pop('delta_scheme', 'xtpl_highest_1')
}
return [scf, corl, delta]
register_composite_function(test_composite)
E_func = energy('test_composite')
Any insights or suggestions from the community would be greatly appreciated. Thank you for your time and expertise.