An investigation was made, of the electronic structures and superconductivities of MgB2 with various lattice parameters, by means of multiple-scattered-Xα calculations. It was shown that the lattice parameters had a great effect upon the superconductivity of MgB2. The results showed that the density of states at the Fermi level decreased with the decreasing lattice parameters. The effects were very more sensitive substantially to the change of the lattice parameter a as compared with that of the lattice parameter c. Correspondingly, the superconducting transition temperature TC decreased correspondingly mainly with decreasing the lattice parameter a. The results were in good agreement with experiment.

Superconducting Properties of MgB2 with Different Lattice Parameters. C.Li, L.Hua: Chinese Physics Letters, 2003, 20, 1128-30