MOLECULAR-ORBITALS CALCULATION ON LIH WITH ALGEBRAIC TREATMENT OF THEINTEGRALS

In this work we employ an algebraic computational method to solve the integrals which arise in the study of diatomic molecules. Using the Sl ater-type orbitals (STO), we obtain analytical solutions for the one-c enter and two-center hybrid and Coulomb integrals. The exchange integr als are considered, as much as possible, in a similar manner. These re sults are used to calculate the electronic properties of the ground st ate of the LiH molecule, by means of a variational calculation using a basis of molecular orbitals. The behavior of the Slater exponents of the atomic orbitals are studied as functions of internuclear distance. We show that the STO undergo a lengthening of their shape when the nu clear separation increases.