Dissecting the hydrogen bond: a Quantum Monte Carlo approach

dc.creatorSterpone, Fabio
dc.creatorSpanu, Leonardo
dc.creatorFerraro, Luca
dc.creatorSorella, Sandro
dc.creatorGuidoni, Leonardo
dc.date2008-06-25
dc.date.accessioned2026-07-07T09:46:42Z
dc.date.available2026-07-07T09:46:42Z
dc.descriptionWe present a variational MonteCarlo (VMC) and lattice regularized diffusion MonteCarlo (LRDMC) study of the binding energy and dispersion curve of the water dimer. As a variation ansatz we use the JAGP wave function, an implementation of the resonating valence bond (RVB) idea. Actually one the aim of the present work is to investigate how the bonding of two water molecules, as a prototype of the hydrogen-bonded complexes, could be described within an JAGP approach. Using a pseudopotential for the inert core of the Oxygen, with a full optimization of the variational parameters, we obtain at the VMC level a binding energy of -4.5(0.1) Kcal/mol, while LRDMC calculations gives -4.9(0.1) Kcal/mol (experiment 5 Kcal/Mol). The calculated dispersion curve reproduces both at the VMC and LRDMC level the miminum position and the curvature.The quality of the WF gives us the possibility to dissect the binding energy in different contributions by appropriately switching off determinantal and Jastrow terms in the JAGP: we estimate the dynamical contribution to the binding energy to be of the order of 1.4(0.2) Kcal/Mol whereas the covalent contribution about 1.0(0.2) Kcal/Mol. JAGP reveales thus a promising WF for describing systems where both dispersive and covalent forces play an important role.
dc.description7 pages, 4 figures. accepted for publication in the Journal of Chemical Theory and Computation
dc.identifierhttps://arxiv.org/abs/0806.4169
dc.identifierhttp://arxiv.org/abs/0806.4169
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/163619
dc.subjectChemical Physics
dc.subjectOther Condensed Matter
dc.titleDissecting the hydrogen bond: a Quantum Monte Carlo approach
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