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International Journal of Quantum Chemistry

Analytic properties of connected moments expansions

Jay D. Mancini, Yu Zhou, P. F. Meier

Published Apr 5, 1994• 38 citations
Publisher

Abstract

Abstract The derivation of the connected moments expansion (CMX) is examined as well as the singularities that arise in the series expansion for the ground‐state energy. Explicit analytic results are presented that show a canceling of these singularities. Also, an alternate moments expansion (AMX) is derived that closely models the CMX but displays a varied computational range. © 1994 John Wiley & Sons, Inc.

DOI
10.1002/qua.560500203

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Abstract The derivation of the connected moments expansion (CMX) is examined as well as the singularities that arise in the series expansion for the ground‐state energy. Explicit analytic results are presented that show a canceling of these singularities. Also, an alternate moments expansion (AMX) is derived that closely models the CMX but displays a varied computational range. © 1994 John Wiley & Sons, Inc.
The connected-moments expansion (CMX) for the ground-state energy is derived from the Horn-Weinstein theorem. This new technique possesses several striking advantages over traditional approaches to calculation of the ground-state energy. Like perturbational theories, the CMX series is conceptually simple but is easier to derive and program and is usually convergent even for very ``crude'' trial kets. Numerical examples reveal potential applicability of CMX for calculation of the correlation energy when the trial ket has the form of multideterminant wave function.