From E_{2g} to other modes : Effects of pressure on electron-phonon   interaction in MgB_2
  We study the effects of pressure on the electron-phonon interaction in MgB_2 using density-functional-based methods. Our results show that the superconductivity in MgB_2 vanishes by 100 GPa, and then reappears at higher pressures. In particular, we find a superconducting transition temperature T_c \~ 2 K for mu*=0.1 at a pressure of 137 GPa. 
Prabhakar P. Singh