Dear Psi4 community,
I’m facing some troubles with a SAPT(DFT) calculation. I’ve read several posts and on March 29th Professor Sherrill wrote that the code was undergoing testing, but maybe things have changed. My input is very simple and contains a dimer in which He atom and Ar atom are the fragments. When I run the calculation using Psi4 1.3.2-ecbda83 version, I got an output with nonphysical energies in the DF-RKS part for the He fragment. For example, this is what I got in Iter 8.
@DF-RKS iter 8: 5.8228501255924
and from that point on an energy about the same value. Of course, the subsequent SAPT calculations will produce meaningless results.
Here my input
#! SAPT(DFT) aug-cc-pVDZ interaction energy between He and Ar atoms.
molecule dimer {
He
--
Ar 1 6.5
units bohr
}
set {
basis aug-cc-pvdz
scf_type df
sapt_dft_grac_shift_a 0.32033
sapt_dft_grac_shift_b 0.19999
}
energy(‘sapt(dft)’, molecule=dimer)
Actually, my system is a little bit more complicated and it consists in endohedral fullerenes. In those cases in which I have fragments like He2, HeNe, HeAr, good results are obtained, but when I use He inside the cage, something alters the DF-RKS part of the program, as in the case of the simple HeAr dimer I mentioned before.
Thanks in advance for your help,
Regards,
Sara