Restoring size consistency of approximate functionals constructed from the adiabatic connection

Abstract

Approximate exchange-correlation functionals built by modeling in a non-linear way the adiabatic connection (AC) integrand of density functional theory have many attractive features, being virtually parameters-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 the second-order perturbation theory.

6 pages, 3 figures

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Cited by in corpus (8)

• Strong-interaction limit of an adiabatic connection in Hartree-Fock theory
• Large coupling-strength expansion of the Møller-Plesset adiabatic connection: From paradigmatic cases to variational expressions for the leading terms
• Local and global interpolations along the adiabatic connection of DFT: A study at different correlation regimes
• Functional Derivative of the Zero Point Energy Functional from the Strong Interaction Limit of Density Functional Theory
• Kinetic correlation functionals from the entropic regularisation of the strictly-correlated electrons problem
• Restoring the Point-and-Charge Gradient Expansion for the Strong Interaction Density Functionals
• Comparing correlation components and approximations in Hartree-Fock and Kohn-Sham theories via an analytical test case study
• Investigation of the exchange-correlation potential of functionals based on the adiabatic connection interpolation