def testOverlapMatrix(self):
        '''
            Longer bond length R=2.5, S(1,2) = S(2,1) gets smaller
            less chance of electrons being between atoms
        '''
        vv = HartreeFock()        
        vv.compute_integrals()
        print 'Overlap matrix S', np.round(vv.S,4)
        
        S = np.array([[1.00000615,0.4507713],[0.4507713, 1.00000615]])
        assert(np.round(vv.S,4) == np.round(S,4)).all()

            Longer bond length R=2.5, S(1,2) = S(2,1) gets smaller
            less chance of electrons being between atoms
        
recipes/Python/578515_Hartree_Fock_SCF/recipe-578515.py