An Assessment of Density Functional Methods for Potential Energy Curves of Nonbonded Interactions: The XYG3 and B97-D Approximations

作者：Vazquez Mayagoitia Alvaro; Sherrill C David^*; Apra Edoardo; Sumpter Bobby G

来源：Journal of Chemical Theory and Computation, 2010, 6(3): 727-734.

DOI：10.1021/ct900551z

A recently proposed double-hybrid functional called XYG3 and a semilocal GGA functional (B97-D) with a semiempirical correction for van der Waals interactions have been applied to study the potential energy curves along the dissociation coordinates of weakly bound pairs of molecules governed by London dispersion and induced dipole forces. Molecules treated in this work were the parallel sandwich, T-shaped, and parallel-displaced benzene dimer, (C6H6)(2); hydrogen sulfide and benzene, H2S center dot C6H6; methane and benzene, CH4 center dot C6H6; the methane dimer, (CH4)(2); and the pyridine dimer, (C5H5N)(2). We compared the potential energy curves of these functionals with previously published benchmarks at the coupled cluster singles, doubles, and perturbative triplets [CCSD(T)] complete-basis-set limit. Both functionals, XYG3 and B97-D, exhibited very good performance, reproducing accurate energies for equilibrium distances and a smooth behavior along the dissociation coordinate. Overall, we found an agreement within a few tenths of one kcal mol(-1) with the CCSD(T) results across the potential energy curves.

• 出版日期2010-3