Ewa
1
Hi,
We would like to extract the two-electron integrals from Psi4. This piece of code:
ene,wfn=energy(‘scf’,molecule=mol, return_wfn=True)
mints = MintsHelper(wfn.basisset())
TWO = mints.ao_eri()
prints the entire array, but can we get a folded list of ERIs (i.e. only those that cannot be obtained from symmetry)?
Best,
Ewa
loriab
2
There’s not a special function, but some combination of mints.ao_eri_shell
also this and some loops (suggested by Daniel) may get what you want.
for(int p = 0; p < nmo; p++){
for(int q = 0; q <= p; q++){
for(int r = 0; r <= p; r++){
int smax = (p==r) ? q+1 : r+1;
for(int s = 0; s < smax; s++){