Laplace-transformed atomic orbital-based Møller-Plesset perturbation theory for relativistic two-component Hamiltonians

Abstract

We present a formulation of Laplace-transformed atomic orbital-based second-order Møller-Plesset perturbation theory (MP2) energies for two-component Hamiltonians in the Kramers-restricted formalism. This low-order scaling technique can be used to enable correlated relativistic calculations for large molecular systems. We show that the working equations to compute the relativistic MP2 energy differ by merely a change of algebra (quaternion instead of real) from their non-relativistic counterparts. With a proof-of-principle implementation we study the effect of the nuclear charge on the magnitude of half-transformed integrals and show that for light elements spin-free and spin-orbit MP2 energies are almost identical. Furthermore, we investigate the effect of separation of charge distributions on the Coulomb and exchange energy con- tributions, which show the same long-range decay with the inter-electronic / atomic distance as for non-relativistic MP2. A linearly scaling implementation is possible if the proper distance behavior is introduced to the quaternion Schwarz-type estimates as for non-relativistic MP2.

accepted for publication in The Journal of Chemical Physics

Cited by in corpus (5)

• The DIRAC code for relativistic molecular calculations
• Relativistic Cholesky-decomposed density matrix MP2
• A lower scaling four-component relativistic coupled cluster method based on natural spinors
• Assessing MP2 frozen natural orbitals in relativistic correlated electronic structure calculations
• Laplace-transformed multi-reference second-order perturbation theories in the atomic and active molecular orbital basis