6 papers
An N-scaling excited-state-specific perturbation theory
Rachel Clune, Jacqueline A. R. Shea, Eric Neuscamman
We show that by working in a basis similar to that of the natural transition orbitals and using a modified zeroth order Hamiltonian, the cost of a recently-introduced perturbative…
A generalized variational principle with applications to excited state mean field theory
Jacqueline A. R. Shea, Elise Gwin, Eric Neuscamman
We present a generalization of the variational principle that is compatible with any Hamiltonian eigenstate that can be specified uniquely by a list of properties. This variational…
Tracking excited states in wave function optimization using density matrices and variational principles
Lan Nguyen Tran, Jacqueline A. R. Shea, Eric Neuscamman
We present a method for finding individual excited states' energy stationary points in complete active space self-consistent field theory that is compatible with standard optimizat…
A Mean Field Platform for Excited State Quantum Chemistry
Jacqueline A. R. Shea, Eric Neuscamman
We present a mean field theory for excited states that is broadly analogous to ground state Hartree-Fock theory. Like Hartree-Fock, our approach is deterministic, state-specific, a…
QMCPACK : An open source ab initio Quantum Monte Carlo package for the electronic structure of atoms, molecules, and solids
Jeongnim Kim, Andrew Baczewski, Todd D. Beaudet +45
QMCPACK is an open source quantum Monte Carlo package for ab-initio electronic structure calculations. It supports calculations of metallic and insulating solids, molecules, atoms,…
Size consistent excited states via algorithmic transformations between variational principles
Jacqueline A. R. Shea, Eric Neuscamman
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 opti…