| Autor: |
Fetherolf JH; Department of Chemistry, Columbia University, New York, New York 10027, USA., Berkelbach TC; Department of Chemistry, Columbia University, New York, New York 10027, USA. |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of chemical physics [J Chem Phys] 2021 Feb 21; Vol. 154 (7), pp. 074104. |
| DOI: |
10.1063/5.0035454 |
| Abstrakt: |
We introduce vibrational heat-bath configuration interaction (VHCI) as an accurate and efficient method for calculating vibrational eigenstates of anharmonic systems. Inspired by its origin in electronic structure theory, VHCI is a selected CI approach that uses a simple criterion to identify important basis states with a pre-sorted list of anharmonic force constants. Screened second-order perturbation theory and simple extrapolation techniques provide significant improvements to variational energy estimates. We benchmark VHCI on four molecules with 12-48 degrees of freedom and use anharmonic potential energy surfaces truncated at fourth and sixth orders. When compared to other methods using the same truncated potentials, VHCI produces vibrational spectra of tens or hundreds of states with sub-wavenumber accuracy at low computational cost. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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