Basis set and correlation effects on computed hydrogen bond energies of the dimers (AHn)2: AHn=NH3, OH2, and FH

Abstract

Basis set expansion and correlation effects on computed hydrogen bond energies of the dimers (AHn)2, AHn=NH3, OH2, and FH, have been evaluated. The addition of diffuse functions is the single most important enhancement of split-valence plus polarization basis sets, leading to a significant lowering of hydrogen bond energies at all levels of theory. In general, basis set enhancement effects do not appear to be additive. The correlation energy contribution increases the stabilization energies of these neutral hydrogen bonded complexes, with the second order Mo/ller–Plesset term being the dominant term.