Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations

Details Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations

2009-07-20

arxiv.org/abs/0907.3469v1

J. Chem. Phys. 131, 124509 (2009)

Physics

Condensed Matter

Materials Science

10 pages, 8 figures, Submitted to Journal of Chemical Physics, Related information can be found in http://www.fhi-berlin.mpg.d

Scientific paper

10.1063/1.3236840

To understand the performance of popular density-functional theory (DFT) exchange-correlation (xc) functionals in simulations of liquid water, water monomers and dimers were extracted from a PBE simulation of liquid water and examined with coupled cluster with single and double excitations plus a perturbative correction for connected triples [CCSD(T)]. CCSD(T) reveals that most of the dimers are unbound compared to two gas phase equilibrium water monomers, largely because monomers within the liquid have distorted geometries. Of the three xc functionals tested, PBE and BLYP systematically underestimate the cost of the monomer deformations and consequently predict too large dissociation energies between monomers within the dimers. This is in marked contrast to how these functionals perform for an equilibrium water dimer and other small water clusters in the gas phase, which only have moderately deformed monomers. PBE0 reproduces the CCSD(T) monomer deformation energies very well and consequently the dimer dissociation energies much more accurately than PBE and BLYP. Although this study is limited to water monomers and dimers, the results reported here may provide an explanation for the overstructured radial distribution functions routinely observed in BLYP and PBE simulations of liquid water and are of relevance to water in other phases and to other associated molecular liquids.

Affiliated with

Also associated with

No associations

Rating

Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-697075