Benchmark of density functional theory for superconductors in elemental materials

Systematic benchmark calculations for elemental bulks are presented to validate the accuracy of density functional theory for superconductors. We developed a method to treat the spin-orbit interaction (SOI) together with the spin fluctuation (SF) and examine their effect on the superconducting transition temperature. We found the following results from the benchmark calculations: (1) The calculations, including SOI and SF, reproduce the experimental superconducting transition temperature (Tc) quantitatively. (2) The effect by SOI is small excepting a few elements, such as Pb, Tl, and Re. (3) SF reduces Tc's, especially for the transition metals, whereas this reduction is too weak to reproduce the Tc's of Zn and Cd. (4) We reproduced the absence of superconductivity for alkaline- (earth) and noble metals. These calculations confirm that our method can be applied to a wide range of materials and implies a direction for the further improvement of the methodology.