Article,

Bounds to electronic expectation values for atomic and molecular systems

, and .
International Journal of Quantum Chemistry, 111 (14): 3588--3596 (November 2011)
DOI: 10.1002/qua.22924

Abstract

A generalization of a method to calculate lower bounds to expectation values of non-negative observables is presented. We consider bounds to three electronic expectation values <r2>, <r>, and <r−1> in the helium atom as an example. For both <r2> and <r>, we are able to calculate improved lower bounds. The lower bound to <r−1> does not improve, but we are able to calculate an upper bound which is much closer to the expectation value than the lower bound. Although our generalization allows for improved bounds and/or upper bounds, these bounds to general observables are much less precise than energy bounds and even the expectation values calculated from variational wave functions.

Tags

Users

  • @drmatusek

Comments and Reviews