Quantum Monte Carlo calculations of the dissociation energies of three-electron hemibonded radical cationic dimers

Gurtubay, I. G. and Drummond, Neil and Towler, M. D. and Needs, R. J. (2006) Quantum Monte Carlo calculations of the dissociation energies of three-electron hemibonded radical cationic dimers. Journal of Chemical Physics, 124 (2): 024318. ISSN 1089-7690

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Abstract

We report variational and diffusion quantum Monte Carlo (VMC and DMC) calculations of the dissociation energies of the three-electron hemibonded radical cationic dimers of He, NH3, H2O, HF, and Ne. These systems are particularly difficult for standard density-functional methods such as the local-density approximation and the generalized gradient approximation. We have performed both all-electron (AE) and pseudopotential (PP) calculations using Slater-Jastrow wave functions with Hartree-Fock single-particle orbitals. Our results are in good agreement with coupled-cluster CCSD(T) calculations. We have also studied the relative stability of the hemibonded and hydrogen-bonded water radical dimer isomers. Our calculations indicate that the latter isomer is more stable, in agreement with post-Hartree-Fock methods. The excellent agreement between our AE and PP results demonstrates the high quality of the PPs used within our VMC and DMC calculations.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Chemical Physics
Uncontrolled Keywords:
/dk/atira/pure/core/keywords/physics
Subjects:
?? physicsgeneral physics and astronomyphysical and theoretical chemistryphysics and astronomy(all)qc physics ??
ID Code:
55609
Deposited By:
Deposited On:
10 Jul 2012 08:35
Refereed?:
Yes
Published?:
Published
Last Modified:
16 Jul 2024 09:05