Gaussian Basis Sets and Finite Nuclei

1 Gaussian basis sets and finite nuclei. - We have already noted in Section 

1 that Gaussian-type functions are a natural choice of basis function for atomic and molecular electronic structure calculations if the point nucleus is abandoned in favour of a more realistic finite nucleus121-124 such as the Fermi nucleus .145 The use of finite nuclear models is not restricted to relativistic electronic structure studies. Indeed, there is some advantage to using such distributed nucleus models in non-relativistic studies since it is known that the convergence of finite basis set expansions is dominated by the ability of the functions to describe cusps.125,126 

---