According to the moleular orbital theory, all atomic orbitals combine to form molecular orbital by `LCAO` (linear combination of atomic orbitals) method When two atomic orbitals have additive (constructive) method When two atomic orbitals have additive (constructive) overlapping they form bonding molecular orbitals `(BMO)` which have lower energy than atomic orbitals whereas when atomic orbitals overlap subtractive higher energy antibonding molecular orbitals `(ABMO)` are formed Each `MO` occupies two electrons with opposite spin Distribution of electrons in `MO` follows Aufbau principle as well as Hund's rule `MO` theory can successfully explain the magnetic behaviour of molecules
`O_(2)^(2-)` will have .