Importance of high-angular-momentum channels in pseudopotentials for quantum Monte Carlo

William W. Tipton, Neil D. Drummond, and Richard G. Hennig
Phys. Rev. B 90, 125110 – Published 5 September 2014
PDFHTMLExport Citation

Abstract

Quantum Monte Carlo methods provide in principle a highly accurate treatment of the many-body problem of calculating the ground and excited states of condensed systems. In practice, however, uncontrolled errors, such as those arising from the fixed-node and pseudopotential approximations can be problematic. We show that the accuracy of some quantum Monte Carlo calculations is limited by the properties of currently available pseudopotentials. The use of pseudopotentials involves several approximations, and we will focus on one that is relatively simple to correct during the pseudopotential design phase. It is necessary to include angular-momentum channels in the pseudopotential for excited angular-momentum states and to choose the local channel appropriately to obtain accurate results. Variational and diffusion Monte Carlo calculations for Zn, O, and Si atoms and ions demonstrate these issues. Adding higher-angular-momentum channels into the pseudopotential description reduces such errors without a significant increase in computational cost.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 21 May 2014
  • Revised 3 August 2014

DOI:https://doi.org/10.1103/PhysRevB.90.125110

©2014 American Physical Society

Authors & Affiliations

William W. Tipton1, Neil D. Drummond2,3, and Richard G. Hennig1

  • 1Department of Materials Science and Engineering, Cornell University, Ithaca, New York, 14853 New York, USA
  • 2Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
  • 3TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 90, Iss. 12 — 15 September 2014

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×