Role of two dimensionality in MgB2

In the theoretical study of the origin of superconductivity in MgB2, the importance of the two dimensionality of the electronic structure has not been clear. Here we use the related system, and predicted superconductor, Li1-xBC to illustrate the importance the two dimensionality of the sigma bands has for (1) the occurrence of high T-c, (2) the possibility of raising the critical temperature, and (3) the lattice instabilities that accompany strong electron-phonon coupling. (C) 2003 Elsevier Science B.V. All rights reserved.