# ‘tripleint_cc’: A program for 2-centre variational leptonic Coulomb potential matrix elements using Hylleraas-type trial functions, with a performance optimization study

## Description

Abstract We present a program used to calculate intricate three-particle integrals for variational calculations of solutions to the leptonic Schrödinger equation with two nuclear centres in which inter-leptonic distances (electron-electron and positron-electron) are included directly in the trial functions. The program has been used so far in calculations of He - over(H, ̄) interactions and positron H _2 scattering, however the precisely define... Title of program: tripleint.cc Catalogue Id: AEEV_v1_0 Nature of problem The 'tripleint.cc' code evaluates three-particle integrals needed in certain variational (in particular: Rayleigh-Ritz and generalized-Kohn) matrix elements for solution of the Schrödinger equation with two fixed centres (the solutions may then be used in subsequent dynamic nuclear calculations). Specifically the integrals are defined by equation (16) in the main text and contain terms proportional to r ik × r jk /r ij , i ≠j , i ≠ k , j ≠ k , with r ij the distance between leptons i and j. The ... Versions of this program held in the CPC repository in Mendeley Data AEEV_v1_0; tripleint.cc; 10.1016/j.cpc.2009.07.008 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)