Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


three-particle Coulomb systems

Calculation of Atomic Integrals with Exponentialy Correlated Functions

A new type of correlation atomic integrals occurring in variation energy calculations of three-particle Coulomb systems is studied. A integrand in them along with an interparticle distance linear term under an exponent additionally contains a quadratic term. It is demonstrated that these integrals are analytically expressed through Faddeeva function of a pure imaginary argument and its derivatives. A stable and fast algorithm for calculation of Faddeeva function derivatives to the twentieth order is developed.