Noncovalent Interactions by Fixed-Node Diffusion Monte Carlo: Convergence of Nodes and Energy Differences vs Gaussian Basis-Set Size
| Autor: | Matúš Dubecký |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Electron density
010304 chemical physics Basis (linear algebra) Chemistry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Computer Science Applications Set (abstract data type) 0103 physical sciences Convergence (routing) Node (circuits) Diffusion Monte Carlo Statistical physics Physical and Theoretical Chemistry Atomic physics 0210 nano-technology Wave function Basis set |
| Zdroj: | Journal of Chemical Theory and Computation. 13:3626-3635 |
| ISSN: | 1549-9626 1549-9618 |
| Popis: | Convergence of fixed-node (FN) shape and FN diffusion Monte Carlo (FNDMC) interaction energies is studied vs the Gaussian basis set saturation level in HF and CH4 dimers and one-determinant Slater-Jastrow trial wave functions (ΨT). The tested 25 distinct basis sets obtained by stepwise trimming of aug-VDZ and aug-VTZ bases suggest minimum basis set requirements to achieve reasonable results. A single selected trimmed basis set, about 2 times smaller in size than aug-VTZ, is extensively tested on a set of 12 noncovalent complexes including formic acid dimer, benzene-methane, or coronene-H2. The results indicate that equivalent noncovalent FNDMC energy differences are available at costs lower than assumed before. Additional insights from electron density differences and comparison of dimer vs monomer ΨT nodes explain this observation. |
| Databáze: | OpenAIRE |
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