Performance of a Nonempirical Density Functional on Molecules and Hydrogen-Bonded Complexes

TL;DR

This paper evaluates the Tao and Mo (TM) meta-GGA density functional's accuracy across various molecular properties and complexes, demonstrating its superior performance over some existing functionals.

Contribution

It provides a comprehensive assessment of the TM functional's performance on standard molecular test sets, highlighting its strengths in specific properties.

Findings

High accuracy for proton affinities and vibrational frequencies

Best results for hydrogen-bonded dissociation energies and bond lengths

Superior to LSDA, PBE, and TPSS functionals in key properties

Abstract

Recently, Tao and Mo (TM) derived a meta-generalized gradient approximation functional based on a model exchange-correlation hole. In this work, the performance of this functional is assessed on standard test sets, using the 6-311++G(3df,3pd) basis set. These test sets include 223 G3/99 enthalpies of formation, 99 atomization energies, 76 barrier heights, 58 electron affinities, 8 proton affinities, 96 bond lengths, 82 harmonic vibrational frequencies, 10 hydrogen-bonded molecular complexes, and 22 atomic excitation energies. Our calculations show that the TM functional can achieve high accuracy for most properties considered, relative to the LSDA, PBE, and TPSS functionals. In particular, it yields the best accuracy for proton affinities, harmonic vibrational frequencies, hydrogen-bonded dissociation energies and bond lengths, and atomic excitation energies.