Document Type
Article
Department/Program
Physics
Journal Title
Journal of Chemical Physics
Pub Date
2016
Volume
144
Issue
24
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 Cr-2 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 Mo-2 dimer has also, to date, been scattered and less than satisfactory. We present high-level theoretical benchmarks of the Mo-2 singlet ground state (X-1 Sigma(+)(g)) and first triplet excited state (a(3)Sigma(+)(u)), 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 Cr-2 and Mo-2. Published by AIP Publishing.
Recommended Citation
Purwanto, Wirawan; Zhang, Shiwei; Krakauer, Henry; and Purwanto, Wirawan, Auxiliary-field quantum Monte Carlo calculations of the molybdenum dimer (2016). Journal of Chemical Physics, 144(24).
10.1063/1.4954245
DOI
10.1063/1.4954245
