[molpro-user] A question about the dummy atom in SAPT calculation in molpro

[cong.wang]

Dear everyone,

 Hello!

 According to the manual of molpro, an example input for SAPT calculation is

r=5.6
geometry={nosym; he1; he2,he1,r}
basis=avqz

!wf records
ca=2101.2
cb=2102.2

!monomer A
dummy,he2
{hf; save,$ca}
sapt;monomerA

!monomer B
dummy,he1
{hf; start,atdens; save,$cb}
sapt;monomerB

!interaction contributions
sapt;intermol,ca=$ca,cb=$cb
*******************************************

My question is, since SAPT is BSSE free, why there is a "dummy" in the
input file? If I omit the "dummy" in the input, the problem is error
terminated.

Thank you very much and best regards
Cong Wang

Ph.D. student
Department of Chemistry
Laboratory for Instruction in Swedish
University of Helsinki
A.I. Virtanens plats 1
P.O. Box 55
FI-00014 University of Helsinki
FINLAND