Auxiliary-field quantum Monte Carlo calculations of the molybdenum dimer
Abstract
Chemical accuracy is difficult to achieve for systems with transition metal atoms. Third row transition metal atoms are particularly challenging due to strong electron-electron correlation in localized d-orbitals. The Cr2 molecule is an outstanding example, which we previously treated with highly accurate auxiliary-field quantum Monte Carlo (AFQMC) calculations [W. Purwanto et al., J. Chem. Phys. 142, 064302 (2015)]. Somewhat surprisingly, computational description of the isoelectronic Mo2 dimer has also, to date, been scattered and less than satisfactory. We present high-level theoretical benchmarks of the Mo2 singlet ground state (X1Σg+) and first triplet excited state (a3Σu+), using the phaseless AFQMC calculations. Extrapolation to the complete basis set limit is performed. Excellent agreement with experimental spectroscopic constants is obtained. We also present a comparison of the correlation effects in Cr2 and Mo2.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 27, 2016
- Source ID
- 10.1063/1.4954245
Entities
People
- Henry Krakauer
- Shiwei Zhang
- Wirawan Purwanto
Organizations
- College of William & Mary
- National Science Foundation
- Office of Naval Research
- United States Department of Energy