2009/08/31 by Norbert Nemec, Michael D. Towler, R. J. Needs · 1 citation
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Advanced Physical and Chemical Molecular Interactions #Cusp (singularity) #Diffusion #Diffusion Monte Carlo #Dynamic Monte Carlo method #Monte Carlo method #Monte Carlo method in statistical physics #Monte Carlo molecular modeling #Quantum #Quantum Monte Carlo #Quantum, superfluid, helium dynamics #Wave function #cond-mat.mtrl-sci #physics.chem-ph
paper · pdf · doi:10.1063/1.3288054
published as J. Chem. Phys. 132, 034111 (2010) · 7 pages, 7 figures, published by J. Chem. Phys (substantial changes after first submission)
openalex publication_date 2010/01/21 · arxiv created 2010/02/11 · arxiv updated 2010/02/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the efficiency, precision and accuracy of all-electron variational and diffusion quantum Monte Carlo calculations using Slater basis sets. Starting from wave functions generated by Hartree-Fock and density functional theory, we describe an algorithm to enforce the electron-nucleus cusp condition by linear projection. For the 55 molecules in the G2 set, the diffusion quantum Monte Carlo calculations recovers an average of 95% of the correlation energy and reproduces bond energies to a mean absolute deviation of 3.2 kcal/mol. Comparing the individual total energies with essentially exact values, we investigate the error cancellation in atomization and chemical reaction path energies, giving additional insight into the sizes of nodal surface errors.