Circulant orbitals for atoms and molecules
AUTOR(ES)
Parr, Robert G.
RESUMO
Circulant orbitals ϕn for a closed-shell system are the orbitals obtained when the N canonical orthonormal Hartree-Fock orbitals λ[unk] are subjected to a unitary transformation which is the discrete Fourier transformation: ϕn = 1/√N Σ[unk]λ[unk]ω(n-1)([unk]-1), where ω = exp(2πi/N). Electron densities associated with the orbitals ϕn are each close to the average total electron density. The Fock matrix, diagonal for canonical orbitals, for circulant orbitals is a Hermitian circulant matrix, εm, m+q = 1/N Σ[unk]ε[unk]ωq([unk]-1), where the ε[unk] are the canonical orbital energies. The states ^Fϕn are uniformly distributed on the surface of a sphere in Hilbert space.
