Calculation of interatomic forces and optimization of molecular geometry with auxiliary-field quantum Monte Carlo
- Creators
- Motta, Mario
- Zhang, Shiwei
Abstract
We propose an algorithm for accurate, systematic, and scalable computation of interatomic forces within the auxiliary-field quantum Monte Carlo (AFQMC) method. The algorithm relies on the Hellmann-Feynman theorem and incorporates Pulay corrections in the presence of atomic orbital basis sets. We benchmark the method for small molecules by comparing the computed forces with the derivatives of the AFQMC potential energy surface and by direct comparison with other quantum chemistry methods. We then perform geometry optimizations using the steepest descent algorithm in larger molecules. With realistic basis sets, we obtain equilibrium geometries in agreement, within statistical error bars, with experimental values. The increase in computational cost for computing forces in this approach is only a small prefactor over that of calculating the total energy. This paves the way for a general and efficient approach for geometry optimization and molecular dynamics within AFQMC.
Additional Information
© 2018 Published by AIP Publishing. Received 15 March 2018; accepted 24 April 2018; published online 8 May 2018. We acknowledge support from NSF (Grant No. DMR-1409510), DOE (Grant No. DE-SC0001303), and the Simons Foundation. Computations were carried out at the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation Grant No. ACI-1053575, at the Storm and SciClone Clusters at the College of William and Mary. M.M. acknowledges James Shee and Qiming Sun for valuable interaction.Attached Files
Published - 1.5029508.pdf
Submitted - 1803.05599.pdf
Supplemental Material - sm.pdf
Files
Additional details
- Eprint ID
- 86276
- Resolver ID
- CaltechAUTHORS:20180508-095250649
- DMR-1409510
- NSF
- DE-SC0001303
- Department of Energy (DOE)
- Simons Foundation
- ACI-1053575
- NSF
- Created
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2018-05-08Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field