Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 21, 2009 | Published
Journal Article Open

A study of cumulant approximations to n-electron valence multireference perturbation theory


We investigate the possibility of reducing the complexity of multireference perturbation theory through cumulant based approximations to the high-order density matrices that appear in such theories. Our test cases show that while the cumulant approximated forms are degraded in accuracy relative to the parent theory and exhibit intruder state problems that must be carefully handled, they may provide a route to a simple estimation of dynamic correlation when the parent perturbation theory is infeasible. Nonetheless, further work is clearly needed on better approximations to the denominators in the perturbation theory.

Additional Information

© 2009 American Institute of Physics. Received 9 January 2009; accepted 21 April 2009; published online 18 May 2009. This work was supported by the National Science Foundation CAREER program (Grant No. CHE-0645380) and the Department of Energy, Office of Science (through Award No. DE-FG02-07ER46432).

Attached Files

Published - 1_2E3132922.pdf


Files (186.2 kB)
Name Size Download all
186.2 kB Preview Download

Additional details

August 20, 2023
August 20, 2023