Funciones tipo Eckart para sistemas atómicos de cuatro y seis electrones

Abstract

The Eckart type functions are defined as a spin non restricted wave function, in which each orbital is described by a single exponential function with adjustable exponent (C. Eckart, Phys. Rev. 86, 878 (1930)). In the present paper, the Eckart type function concept is extended to the projected and half-projected Hartree-Fock models. The corresponding Eckart type functions may be the considered as approximations for these models. The corresponding Eckart type functions may be the considered as approximations for these models. The quality of these approaches is checked in the case of the beryllium atom, and an application to the study of 3p state of the carbon atom is presented. The utility of the Eckart type functions is discussed, and some generalizations of them to other models are considered.