AN ALTERNATIVE DERIVATION OF PROPERTIES OF ALTERNANT MOLECULAR ORBITAL WAVE FUNCTION

The properties of the Alternant Molecular Orbital wave function are derived using the spin projection in the form of a weighted average of rotated determinants. As an example of a two-body spin-independent operator the Coulomb repulsion is considered. Also the case of spin-dependent operators of rank one is treated. It is shown that the formal analysis is simpler than with the projection method used previously and a compact expression is given for the coefficients relating the expectation values in the A.M.O. function to the matrix elements between the Molecular Orbitals. © 1969.