[molpro-user] N2O CCSD(T)/cc-pVDZ calculation disagrees with NWChem

[Robert Hinde]

Dear Molpro user community:

I'm trying to use the file below to compute the frozen-core
CCSD(T)/cc-pVDZ energy for N2O.  The results that I get using
Molpro version 2008.1 are

E[SCF] = -183.689956
E[CCSD] = -184.208711
E[CCSD(T)] = -184.235475

The SCF and CCSD energies agree with a calculation done using
NWChem; however, NWChem reports the CCSD(T) energy to be

E[CCSD(T)] = -184.233981

which agrees with the literature [J. Phys. Chem. A vol. 104,
p. 1304 (2000), which cites in turn J. Chem. Phys. vol. 100,
p. 8186 (1994)].  A Dalton calculation gives the same CCSD(T)
energy as that reported by NWChem.

Is there some obvious mistake in my Molpro input file?

I should also note that if, rather than using basis=pvdz, I
explicitly define the basis using text copied from the EMSL
basis set exchange, I get the same SCF and CCSD energies, but
the CCSD(T) energy changes to

E[CCSD(T)] = -184.235529

Thanks,
RJH

-----

***,I
memory,275,M;

gprint,orbitals,civector,basis;

geometry={
N1;
N2,N1,2.16903;
O,N2,2.25879,N1,180;
}

basis=vdz;

{hf;wf,22,1,0;occ,7,2,2;}
ccsd(t);

-----

Robert Hinde
Professor and Director of Graduate Studies,
   Department of Chemistry
Associate Dean for Teaching and Diversity,
   College of Arts and Sciences
University of Tennessee