Molecular Orbital Theory: Spinor Representation

Abstract

The algebra representing electron is spinor. The many electron problem is investigated with the Nambu 2×2 spinor. Operators then are expressed 2×2 matrices. The electron–electron interaction is decomposed into couplings between various electron densities by using the Pauli spin matrices. The diagonal ones of them refer to the direct and exchange interactions and the off-diagonal terms to those for superconducting. The Roothaan theory is rewritten. The approximation beyond the Hartree–Fock is discussed.