title: Breathing orbital valence bond method in diffusion Monte Carlo: C-H bond dissociation of acetylene.
abstract: This study explores the use of breathing orbital valence bond (BOVB) trial wave functions for diffusion Monte Carlo (DMC). The approach is applied to the computation of the carbon-hydrogen (C-H) bond dissociation energy (BDE) of acetylene. DMC with BOVB trial wave functions yields a C-H BDE of 132.4 +/- 0.9 kcal/mol, which is in excellent accord with the recommended experimental value of 132.8 +/- 0.7 kcal/mol. These values are to be compared with DMC results obtained with single determinant trial wave functions, using Hartree-Fock orbitals (137.5 +/- 0.5 kcal/mol) and local spin density (LDA) Kohn-Sham orbitals (135.6 +/- 0.5 kcal/mol).
authors.affiliation: Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460, USA.
authors.forename: Dominik
authors.initials: D
authors.lastname: Domin
authors.forename: Benoît
authors.initials: B
authors.lastname: Braïda
authors.forename: William A
authors.initials: WA
authors.lastname: Lester