The molecular orbital configuration of species O22− is shown below. O22−:(σ1s)2,(σ*1s)2,(σ2s)2,(σ*2s)2,(σ2pz)2,(π2px)2≈(π2py)2,(π*2px)2≈(π*2py)2 In bonding orbitals, there are total 10 electrons. In antibonding orbitals, there are total 8 electrons.