EAGER: Correlator product states for quantum chemistry and quantum Monte Carlo

Cornell University, Ithaca NY

Investigators

Abstract

Garnet K. Chan and Cyrus Umrigar of Cornell University are funded by an EAGER award from the Theory, Models and Computational Methods program to explore a novel class of electronic wave functions. Such wave functions have the potential of creating a new quantum chemistry framework enabling studies of electronic structure with global inclusion of electron correlation. The new approach involves groups of states referred as Correlator Product States (CPS) that are fundamentally different from the wave functions used in established electronic structure approaches such as configuration interaction, coupled cluster, geminal, among others. Initial studies on model systems show that CPS can describe strongly correlated quantum problems more accurately and more efficiently than other classes of wave functions. In this exploratory project the CPS approach is extended to describe dissociation of small molecules and elemental clusters. The new wave functions are very useful as the starting point in diffusion quantum Monte Carlo studies. Currently steps are underway to show that the CPS ansatz provides the framework for understanding an entire class of electronic correlations that are central to transition metal chemistry, excited states, bond-breaking, and complex materials. Broader impacts are achieved by the transformative approach to explore electronic structure studies that affect a broad audience of chemists and material scientists using quantum chemistry and quantum Monte Carlo methodologies.