  The method of mathematical modeling was used for the calculation of the
structural, electronic, phonon, and other characteristics of various normal
phases of phosphorus hydrides with stoichiometry PHk. It was shown that the
di-phosphine may form 2D lattice of the metallic hydrogen, stabilized by
phosphorus atoms under high hydrostatic compressive pressure. The resulting
structure with the elements of H-P-H is a locally stable one in the phonon
spectrum (or metastable). The properties of di-phosphine with the properties of
similar structures such as thesulphur hydrides were compared.
