Excitation Variance Matching with Limited Configuration Interaction Expansions in Variational Monte Carlo

Autor: Robinson, Paul J., Flores, Sergio D. Pineda, Neuscamman, Eric
Rok vydání: 2017
Předmět:
Zdroj: J. Chem. Phys. 147, 164114 (2017)
Druh dokumentu: Working Paper
DOI: 10.1063/1.5008743
Popis: In the regime where traditional approaches to electronic structure cannot afford to achieve accurate energy differences via exhaustive wave function flexibility, rigorous approaches to balancing different states' accuracies become desirable. As a direct measure of a wave function's accuracy, the energy variance offers one route to achieving such a balance. Here, we develop and test a variance matching approach for predicting excitation energies within the context of variational Monte Carlo and selective configuration interaction. In a series of tests on small but difficult molecules, we demonstrate that the approach it is effective at delivering accurate excitation energies when the wave function is far from the exhaustive flexibility limit. Results in C$_3$, where we combine this approach with variational Monte Carlo orbital optimization, are especially encouraging.
Comment: 11 pages, 7 figures, 2 tables
Databáze: arXiv