Density matrices in full configuration interaction quantum Monte Carlo: Excited states, transition dipole moments, and parallel distribution

Abstract

We present developments in the calculation of reduced density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently introduced excited-state FCIQMC approach [N. S. Blunt et al., J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of transition density matrices in the method. These approaches are combined to calculate excited-state dipole and transition dipole moments for heteronuclear diatomic molecules, including LiH, BH, and MgO, and initiator error is investigated in these quantities.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 26, 2017
Source ID
10.1063/1.4986963

Entities

People

  • Ali Alavi
  • George H Booth
  • N. S. Blunt

Organizations

  • Air Force Office of Scientific Research
  • Engineering and Physical Sciences Research Council
  • King's College London
  • Max Planck Institute for Solid State Research
  • Max Planck Society
  • Royal Society
  • Trinity College
  • Yusuf Hamied Department of Chemistry

Tags

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Quantum Chemistry
  • Statistical inference.

Technology Areas

  • Quantum Computing