Crystal structure and superconductivity in Re2Si

The rhenium-rich phase Re2Si crystallizes in a monoclinic unit cell, a = 6.4444(2) Å, b = 5.3898(2) Å, c = 9.6019(4) Å, γ = 94.215(5)° (unique axis c, Pearson symbol mP24, Z = 8 and space group P21b. The structure is based on a hexagonal close packing of rhenium and silicon atoms ordered on distinct sites and represents a new structure type. Re2Si becomes superconducting below 3.8 K.