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The size-extensitivity of correlation energy estimators based on effective characteristic polynomials

Chemical Physics 2011-08-19 v1 Mathematical Physics math.MP Numerical Analysis Computational Physics

Abstract

Estimators Πn\Pi n for the correlation energy can be computed as roots of effective characteristic polynomials of degree nn. The coefficients of these polynomials are derived from the terms of the perturbation series of the energy. From a fourth-order M{\o}ller-Plesset (MP4) calculation one can calculate with negligible effort a size-extensive estimator Π2\Pi 2 that is in many cases much closer to the full CI correlation energy of the ground state than the MP4 value. [H.H.H. Homeier, J. Mol. Struct. (Theochem) 366, 161 (1996)] Here, we prove that the estimators Πn\Pi n for n>2n>2 are size-extensive if they are calculated from the MP series.

Cite

@article{arxiv.physics/9704004,
  title  = {The size-extensitivity of correlation energy estimators based on effective characteristic polynomials},
  author = {Herbert H. H. Homeier},
  journal= {arXiv preprint arXiv:physics/9704004},
  year   = {2011}
}

Comments

6 pages, 10 references, LaTeX2e, elsart.cls, J. Mol. Struct. (THEOCHEM), in press. Paper 27 at the 3$^{rd}$ Electronic Computational Chemistry Conference, 1996. Postscript and dvi also available via http://www.chemie.uni-regensburg.de/preprint.html

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