AM05 Density Functional Applied to the Water Molecule, Dimer, and Bulk Liquid

Ann E Mattsson; Thomas R Mattsson

doi:10.1021/ct8004968

AM05 Density Functional Applied to the Water Molecule, Dimer, and Bulk Liquid

J Chem Theory Comput. 2009 Apr 14;5(4):887-94. doi: 10.1021/ct8004968.

Authors

Ann E Mattsson¹, Thomas R Mattsson¹

Affiliation

¹ Multiscale Dynamic Materials Modeling, MS 1322, Sandia National Laboratories, Albuquerque, New Mexico 87185-1322, and High Energy Density Physics Theory, MS 1189, Sandia National Laboratories, Albuquerque, New Mexico 87185-1189.

PMID: 26609597
DOI: 10.1021/ct8004968

Abstract

We compare results for water obtained with the AM05 exchange-correlation density functional ( Armiento, R.; Mattsson, A. E. Phys. Rev. B 2005, 72, 085108 ) with those obtained with five other pure functionals: LDA, PBE, PBEsol, RPBE, and BLYP. For liquid water, AM05 yields an O-O pair correlation function that is more structured than the ones of PBE and BLYP, which, in turn, are more structured than the one of RPBE. However, LDA and PBEsol yields more structured water than AM05. We show that AM05 yields a H2O dimer binding energy of 4.9 kcal/mol. The result is thus within 0.15 kcal/mol of CCSD(T) level theory (5.02 ± 0.05 kcal/mol). We confirm that accuracy in the water dimer binding energy is not a strong indicator for the fidelity of the resulting structure of liquid water.