MO of Li2 and Be2 2s 02s 01s 01s Is Is Is 12 Be B Ground State Electron Configuration in MO Li2:(σ1)2(os)2(a2s Be2:(σ1)2(o1)2(2)2(o23)2 Li,: KK(o2) Be2:KK(σ2)2(2MO of Li2 and Be2 5 Ground State Electron Configuration in MO Li2 :（σ1s)2（σ1s *)2 （σ2s)2 Be2 :（σ1s)2 （σ1s *)2 （σ2s)2 （σ2s *)2 Li2 : KK（σ2s)2 Be2 : KK（σ2s)2 （σ2s *)2