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Restoring Size Consistency of Approximate Functionals Constructed from the Adiabatic Connection.

ABSTRACT: Approximate exchange-correlation functionals built by modeling in a nonlinear way the adiabatic connection (AC) integrand of density functional theory have many attractive features, being virtually parameter-free and satisfying different exact properties, but they also have a fundamental flaw: they violate the size-consistency condition, crucial to evaluate interaction energies of molecular systems. We show that size consistency in the AC-based functionals can be restored in a very simple way at no extra computational cost. Results on a large set of benchmark molecular interaction energies show that functionals based on the interaction strength interpolation approximations are significantly more accurate than second-order perturbation theory.

SUBMITTER: Vuckovic S

PROVIDER: S-EPMC5994725 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Restoring Size Consistency of Approximate Functionals Constructed from the Adiabatic Connection.

Vuckovic Stefan S Gori-Giorgi Paola P Della Sala Fabio F Fabiano Eduardo E

The journal of physical chemistry letters 20180529 11

Approximate exchange-correlation functionals built by modeling in a nonlinear way the adiabatic connection (AC) integrand of density functional theory have many attractive features, being virtually parameter-free and satisfying different exact properties, but they also have a fundamental flaw: they violate the size-consistency condition, crucial to evaluate interaction energies of molecular systems. We show that size consistency in the AC-based functionals can be restored in a very simple way at ...[more]

PMID: 29787273

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