Communication: A novel implementation to compute MP2 correlation energies without basis set superposition errors and complete basis set extrapolation

Abstract

By using a formulation based on the dynamical polarizability, we propose a novel implementation of second-order Møller-Plesset perturbation (MP2) theory within a plane wave (PW) basis set. Because of the intrinsic properties of PWs, this method is not affected by basis set superposition errors. Additionally, results are converged without relying on complete basis set extrapolation techniques; this is achieved by using the eigenvectors of the static polarizability as an auxiliary basis set to compactly and accurately represent the response functions involved in the MP2 equations. Summations over the large number of virtual states are avoided by using a formalism inspired by density functional perturbation theory, and the Lanczos algorithm is used to include dynamical effects. To demonstrate this method, applications to three weakly interacting dimers are presented. Published by AIP Publishing.

Bridging molecular dynamics and correlated wave-function methods for accurate finite-temperature properties

“…and coupled-cluster theory [5] (CC) have long been used [6]. For condensed phase applications, MP2 has only recently appeared -using plane-wave [7,8], localized [9], and hybrid [10] basis sets. Approximations based on coupledcluster theory have been implemented in the VASP [11] and PySCF codes [12,13].…”

Assessing the Accuracy of Machine Learning Thermodynamic Perturbation Theory: Density Functional Theory and Beyond

“…However, the I w index can be straightforwardly obtained and we present its values in Table (7). This type of analysis, which we did not develop in the original paper, Ref.…”

“…While not strictly necessary, the accuracy can be further confirmed by applying MLMC, which requires several additional production level calculations but avoids completely the highly expensive RPA calculations. To this purpose we consider a subset of the systems in Table (7) (the two adsorbed systems with the lowest I w and the two zeolites). With respect to the MLPT values reported in Ref.…”

“…Correlated quantum chemical methods could provide an alternative to density functional theory (DFT) in (periodic) materials simulations possibly reaching the threshold of chemical accuracy (1 kcal/mol) with respect to experimental data. Traditional quantum chemical methods, such as Møller-Plesset perturbation theory to second order (MP2) 1 or coupledcluster theory 2 , have been recently implemented for condensed phase materials applications [3][4][5][6][7] . An alternative particularly suitable for condensed matter applications is represented by the random phase approximation (RPA) [8][9][10][11][12][13][14] and it variants which include higher order corrections [15][16][17][18][19][20][21] .…”

Methods for converging correlation energies within the dielectric matrix formalism

“…The approach described in this section to converge energy differences has been previously used for homogeneous 11,13,59 and heterogeneous systems 15,16,67 . In this work we will systematically study its accuracy for weakly bound systems and reaction energies involving the breaking and formation of covalent bonds (see Sec.…”