# H2SOLV: Fortran solver for diatomic molecules in explicitly correlated exponential basis

## Description

Abstract We present the Fortran package H2SOLV for an efficient computation of the nonrelativistic energy levels and the wave functions of diatomic two-electron molecules within the Born–Oppenheimer approximation. The wave function is obtained as a linear combination of the explicitly correlated exponential (Kołos–Wolniewicz) functions. The computations of H2SOLV are performed within the arbitrary-precision arithmetics, where the number of working digits can be adjusted by the user. The key part of H2... Title of program: H2SOLV Catalogue Id: AFBA_v1_0 Nature of problem Numerical solution of the two-center two-electron Schrödinger equation within the Born-Oppenheimer approximation using the explicitly correlated basis set of Kolos-Wolniewicz functions. Versions of this program held in the CPC repository in Mendeley Data AFBA_v1_0; H2SOLV; 10.1016/j.cpc.2016.07.024 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)