Pressure effects on the electronic structure and superconducting critical temperature of Li2B2

We present the structural, electronic and superconducting properties of Li2B2 under pressure within the framework of the density functional theory. The structural parameters, electronic band structure, phonon frequency of the E(2)g phonon mode and superconducting critical temperature Tc were calculated for pressures up to 20 GPa. We predicted that the superconducting critical temperature of Li2B2 is about 11 K and this decreases as pressure increases. We found that even though the lattice dynamics of the E(2)g phonon mode is similar to MgB2, the reduction of the sigma - band density of states at Fermi level and the raising of the E(2)g phonon frequency with pressure were determinant to decrease lambda and consequently T-c.