  The electronic and lattice dynamical properties of compressed solid SiH$_{4}$
have been calculated in the pressure range up to 300 GPa with density
functional theory. We find that structures having a layered network with
eight-fold SiH$_{8}$ coordination favor metallization and superconductivity.
SiH$_{4}$ in these layered structures is predicted to have superconducting
transition temperatures ranging from 20 to 80 K, thus presenting new
possibilities for exploring high temperature superconductivity in this
hydrogen-rich system.
