Shea Jacqueline A R, Neuscamman Eric
Department of Chemistry, University of California , Berkeley, California 94720, United States.
Chemical Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
J Chem Theory Comput. 2017 Dec 12;13(12):6078-6088. doi: 10.1021/acs.jctc.7b00923. Epub 2017 Nov 30.
We demonstrate that a broad class of excited state variational principles is not size consistent. In light of this difficulty, we develop and test an approach to excited state optimization that transforms between variational principles to achieve state selectivity, size consistency, and compatibility with quantum Monte Carlo. To complement our formal analysis, we provide numerical examples that confirm these properties and demonstrate how they contribute to a more black box approach to excited states in quantum Monte Carlo.
