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Benchmark interaction energies for biologically relevant noncovalent complexes containing divalent sulfur...

by Benjamin J Mintz, Jerry M Parks
Publication Type
Journal Name
Journal of Physical Chemistry
Publication Date
Page Numbers
1086 to 1092

Molecules containing divalent sulfur can participate in significant hydrogen bonding interactions.
Computing accurate noncovalent interaction energies requires a proper description
of electron correlation effects. Coupled-cluster theory with single and double substitutions
and perturbutative triple substitutions, CCSD(T), using extrapolation to the complete basis set
(CBS) limit has become the method of choice for computing accurate interaction energies of
noncovalently bound complexes. Following the procedure used to develop the S66 benchmark
set of noncovalent interaction energies relevant to biomolecular structures [J. Chem. Theory
Comput. (2011)], interaction energies are computed for ten hydrogen-bonded complexes of
biological relevance that contain divalent sulfur. Equilibrium geometries and eight-point estimated
CCSD(T)/CBS potential energy curves along the noncovalent interaction vector are computed for each complex. As a comparison of high-accuracy ab initio methods, interaction
energies are also calculated using the correlation-consistent Composite Approach (ccCA). We
find that the two methods yield energies within a few hundredths of a kcal mol^-1 of each other
in nearly all cases. The interaction energies provided here should be useful for developing and
assessing the accuracy of more approximate ab initio, density functional theory, semi-empirical
and classical force field approaches.