Abstract
The molecular orbital energy level diagram of LiH in conventional textbooks for quantum chemistry is incorrect from viewpoint of ab initio Hartree-Fock SCF-MO calculation, because the 2σlevel of LiH is drawn at a lower position than the 1s orbital of H. It means that the 1s electron of H is stabilized by forming LiH. We show an molecular orbital energy level diagram of LiH obtained by ab initio Hartree-Fock SCF-MO calculation with 6-311++G** basis set in this note. The 2σlevel of LiH is drawn at a higher position than the 1s of H in this diagram. The 1s electron of H is thus destabilized in LiH. Since the 2s electron of Li comes close to the H atom, the 1s electrons of H in 2σorbital are destabilized by electron repulsion.
