Layered Structures Favor Superconductivity in Compressed Solid SiH$_{4}$*

The electronic and lattice-dynamics properties of compressed solid SiH$_{4}$ have been calculated over the pressure regime up to 300 GPa with density functional theory. We find that the structures having layered network with eight-fold SiH$_{8}$ coordination favor the metallization and superconductivity. The layered $Cmca$ SiH$_{4}$ is predicted to have a superconducting transition temperature of 75 K at 70 GPa thus opening new possibilities for exploring high temperature superconductivity in the hydrogen-rich system.