SEARCH Articles Figures Tables Approximate Molecular Orbital Theory for 4-Electron 3-Centre Bonding Units Electron excitation probability atomic orbitals approximation Electron orbitals Electron repulsion orbitals, an approximation Electron, orbiting Many-electron wave functions atomic orbitals approximation Orbital approximation Orbital electrons Orbitals approximation The Wavefunctions of Many-Electron Atoms Can Be Described to a Good Approximation Using Atomic Orbitals