Natural spin orbital analysis of diatomic molecular wave functions in terms of generalized diatomic orbitals I. Outline of the method. Results for the ground state of H2

The method of linear combinations of generalized diatomic orbitals (LCGDO) is combined with the method of configuration interaction (CI). CI wave functions obtained in this way are finally submitted to a natural spin orbital analysis; the resulting natural spin orbitals are expansions in terms of generalized diatomic orbitals.For the ground state of H₂, a one-determinantal-approach with a single completely optimized one-electron basis function nearly reproduces the Hartree-Fock-result. The two-determinantal approach with two optimized basis functions of type _g and _u nearly gives the optimized double configuration SCF result.