Approaching exact hyperpolarizabilities via sum-over-states Monte Carlo configuration interaction

Abstract

We propose using sum-over-states calculations with the compact wavefunctions of Monte Carlo configuration interaction to approach accurate values for higher-order dipole properties up to second hyperpolarizabilities in a controlled way. We apply the approach to small systems that can generally be compared with full configuration interaction (FCI) results. We consider hydrogen fluoride with a 6-31g basis and then look at results, including frequency dependent properties, in an aug-cc-pVDZ basis. We extend one calculation beyond FCI by using an aug-cc-pVTZ basis. The properties of an H${}_4$ molecule with multireference character are calculated in an aug-cc-pVDZ basis. We then investigate this method on a strongly multireference system with a larger FCI space by modelling the properties of carbon monoxide with a stretched geometry. The behavior of the approach with increasing basis size is considered by calculating results for the neon atom using aug-cc-pVDZ to aug-cc-pVQZ. We finally test if the unusual change in polarizability between the first two states of molecular oxygen can be reproduced by this method in a 6-31g basis.

11 pages, 14 figures

References in corpus (3)

• Applying Monte Carlo configuration interaction to transition metal dimers: exploring the balance between static and dynamic correlation
• Calculations of Potential Energy Surfaces Using Monte Carlo Configuration Interaction
• Monte Carlo configuration interaction applied to multipole moments, ionisation energies and electron affinities

Cited by in corpus (1)

• Multireference X-Ray Emission and Absorption Spectroscopy calculations from Monte Carlo Configuration Interaction