Question
What is a linear combination of atomic orbitals (LCAO) far obtaining molecular orbitals ?
Solution
Molecular orbitals are formed by the combination of atomic orbitals. On combining two atomic orbitals, we get two molecular orbitals; one molecular orbital with lower energy is called bonding molecular orbital and its wave function is obtained by the linear addition of wave function and ΨA and ΨB of bonded atoms A and B.
ΨMO = ΨA + ΨB (Bonding MO)
The other molecular orbital with higher energy is called antibonding molecular orbital and its wave function is obtained by linear subtraction of wave functions of ΨA and Ψ B of atomic orbitals.
ΨMO = ΨA – ΨB (Antibonding MO).
