CORRELATION ENERGY OF THE (1s) 2 2s STATE OF THE Be+1AND B+2 IONS

Abstract

A configuration interaction method is used to calculate the correlation energy of (1s) 2 2s state for the Beryllium and Boron ions. The specific form of the configurations used for the systems studied here is linear combination of Slater determinants taken from Weiss with expansion lengths equal to (18). The difference between correlated energy and energy (correlation energy) was found to be (-0.01476 a.u) to Beryllium ion,(-0.00787a.u) to Boron ion. Our calculations were also made on the expectation values for the two above ions.