Engineering superconductors with ab initio methods: the example of LiB

The identification of novel crystal structures is a fundamental step for predicting new stable compounds in alloys. While performing ab initio data mining of intermetallic compounds [1], we discover a new family of layered metal borides [2], of which MgB$_2$ is one particular element (the new phases are called Metal Sandwich (MS)). Thermodynamic stability and electronic properties of these MS phases are investigated in details, leading to the prediction of a hypothetical novel superconductor MS-LiB [2,3]. Calculations show that the MS phases in the Li-B system exhibit electronic features similar to those of MgB$_2$ [2,3] and CaC$_6$ [4]. Although the predicted critical temperature of LiB is lower than that of MgB$_2$ (references [4] and [5] for MS2-LiB and MS1-LiB, respectively), the peculiarities of MS-LiB in terms of electronic structure, layer arrangements and doping capabilities allow a lot of freedom in the search for higher $T_c$ systems [5]. We acknowledge the San Diego Supercomputer Center for computational resources. \newline \newline [1] S. Curtarolo et al., Phys. Rev. Lett. {\bf 91}, 135503 (2003). \newline [2] A.N. Kolmogorov, S. Curtarolo, Phys. Rev. B {\bf 73}, 180501(R) (2006). \newline [3] A.N. Kolmogorov, S. Curtarolo, in press, Phys. Rev B {\bf 74} (2006), condmat/0607654. \newline [4] A.Y. Liu, I.I. Mazin, cond-mat/0610057. \newline [5] M. Calandra, A.N. Kolmogorov, S. Curtarolo, submitted (2006).