Abstract: We developed a code for ab-initio variational configuration interaction calculation of electronic structure of atoms via generalised Laguerre type orbitals. By computing absolute minimum of energy with orbital effective charges as variational parameters optimal wave functions are obtained. Algorithm and program structure are presented in details. A convergence study of our CI method with NMCSCF is given for He 1s²¹S state. It shows that convergence of our CI method is faster than that of NMCSCF method. As an example, absolute minimum of energy and optimal wave functions of Ti in ⁵G states are calculated.

Key words: generalization of Laguerre type orbitals, configuration interaction, electronic structure, optimal wave function