Two exchange-correlation functionals compared for first-principles liquid water

Fernández-Serra, M. V. and Ferlat, G. and Artacho, E. (2005) Two exchange-correlation functionals compared for first-principles liquid water. Molecular Simulation, 31 (5). pp. 361-366. DOI

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The first-principles description of liquid water using ab initio molecular dynamics (AIMD) based on density functional theory (DFT) has recently been found to require long equilibration times, giving too low diffusivities and a clear over-structuring of the liquid. In the light of these findings we compare here the room-temperature description offered by two different exchange correlation functionals: BLYP, the most popular for liquid water so far, and RPBE, a revision of the widely used PBE. We find for RPBE a less structured liquid with radial distribution functions closer to experiment ones than the ones of BLYP. The diffusivity obtained with RPBE for heavy water is still 20% lower than the corresponding experimental value, but it represents a substantial improvement on the BLYP value, one order of magnitude lower than experiment. These characteristics and the hydrogen-bond (HB) network imperfection point to an effective temperature ∼3% lower than the actual simulation temperature for the RPBE liquid, as compared with BLYP's ∼17% deviation. The too long O-O average nearest-neighbor distance observed points to an excessively weak HB, possibly compensating more fundamental errors in the DFT description.

Item Type: Article
Uncontrolled Keywords: 2005 AREP IA46 IA48 2005 P
Subjects: 03 - Mineral Sciences
Divisions: 03 - Mineral Sciences
Journal or Publication Title: Molecular Simulation
Volume: 31
Page Range: pp. 361-366
Identification Number:
Depositing User: Sarah Humbert
Date Deposited: 13 May 2011 16:52
Last Modified: 23 Jul 2013 09:58

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