Cluster perturbation theory. IV. Convergence of cluster perturbation series for energies and molecular properties

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Cluster perturbation theory. IV. Convergence of cluster perturbation series for energies and molecular properties. / Pawlowski, Filip; Olsen, Jeppe; Jørgensen, Poul.

In: The Journal of Chemical Physics, Vol. 150, No. 13, 134111, 2019.

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@article{d89897739a5a49628c0cb48aa001259d,
title = "Cluster perturbation theory. IV.: Convergence of cluster perturbation series for energies and molecular properties",
abstract = "The theoretical foundation has been developed for establishing whether cluster perturbation (CP) series for the energy, molecular properties, and excitation energies are convergent or divergent and for using a two-state model to describe the convergence rate and convergence patterns of the higher-order terms in the CP series. To establish whether the perturbation series are convergent or divergent, a fictitious system is introduced, for which the perturbation is multiplied by a complex scaling parameter z. The requirement for convergent perturbation series becomes that the energy or molecular property, including an excitation energy, for the fictitious system is an analytic, algebraic function of z that has no singularities when the norm |z| is smaller than one. Examples of CP series for the energy and molecular properties, including excitation energies, are also presented, and the two-state model is used for the interpretation of the convergence rate and the convergence patterns of the higher-order terms in these series. The calculations show that the perturbation series effectively become a two-state model at higher orders.",
keywords = "BASIS-SETS, DIVERGENCE, NEON, PLESSET, SPACE",
author = "Filip Pawlowski and Jeppe Olsen and Poul J{\o}rgensen",
year = "2019",
doi = "10.1063/1.5053622",
language = "English",
volume = "150",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "AMER INST PHYSICS",
number = "13",

}

RIS

TY - JOUR

T1 - Cluster perturbation theory. IV.

T2 - Convergence of cluster perturbation series for energies and molecular properties

AU - Pawlowski, Filip

AU - Olsen, Jeppe

AU - Jørgensen, Poul

PY - 2019

Y1 - 2019

N2 - The theoretical foundation has been developed for establishing whether cluster perturbation (CP) series for the energy, molecular properties, and excitation energies are convergent or divergent and for using a two-state model to describe the convergence rate and convergence patterns of the higher-order terms in the CP series. To establish whether the perturbation series are convergent or divergent, a fictitious system is introduced, for which the perturbation is multiplied by a complex scaling parameter z. The requirement for convergent perturbation series becomes that the energy or molecular property, including an excitation energy, for the fictitious system is an analytic, algebraic function of z that has no singularities when the norm |z| is smaller than one. Examples of CP series for the energy and molecular properties, including excitation energies, are also presented, and the two-state model is used for the interpretation of the convergence rate and the convergence patterns of the higher-order terms in these series. The calculations show that the perturbation series effectively become a two-state model at higher orders.

AB - The theoretical foundation has been developed for establishing whether cluster perturbation (CP) series for the energy, molecular properties, and excitation energies are convergent or divergent and for using a two-state model to describe the convergence rate and convergence patterns of the higher-order terms in the CP series. To establish whether the perturbation series are convergent or divergent, a fictitious system is introduced, for which the perturbation is multiplied by a complex scaling parameter z. The requirement for convergent perturbation series becomes that the energy or molecular property, including an excitation energy, for the fictitious system is an analytic, algebraic function of z that has no singularities when the norm |z| is smaller than one. Examples of CP series for the energy and molecular properties, including excitation energies, are also presented, and the two-state model is used for the interpretation of the convergence rate and the convergence patterns of the higher-order terms in these series. The calculations show that the perturbation series effectively become a two-state model at higher orders.

KW - BASIS-SETS

KW - DIVERGENCE

KW - NEON

KW - PLESSET

KW - SPACE

UR - http://www.scopus.com/inward/record.url?scp=85063898562&partnerID=8YFLogxK

U2 - 10.1063/1.5053622

DO - 10.1063/1.5053622

M3 - Journal article

VL - 150

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 13

M1 - 134111

ER -