  Tetragonal Mo5PB2 compound, a recently discovered superconductor, belongs to
technologically important class of materials. It is quite surprising to note
that a large number of physical properties of Mo5PB2, including elastic
properties and their anisotropy, acoustic behavior, electronic (charge density
distribution, electron density difference), thermo-physical, bonding
characteristics, and optical properties have not been carried out at all. In
the present work we have explored all these properties in details for the first
time with density functional theory based first-principles method. Mo5PB2 is
found to be a mechanically stable, elastically anisotropic compound with
ductile character. Moreover, the chemical bonding is interpreted by calculating
the electronic energy density of states, electron density distribution, elastic
properties and Mulliken bond population analysis. Mo5PB2 has a combination of
mainly ionic, metallic, and some covalent bonding characteristics. The compound
possesses high level of machinability. The band structure along with a large
electronic density of states at the Fermi level reveals metallic character.
Calculated values of different thermal parameters of Mo5PB2 are closely related
to the elastic properties. The energy dependent optical parameters show close
assent to the underlying electronic band structure. The optical absorption and
reflectivity spectra and the low energy index of refraction of Mo5PB2 show that
the compound holds promise to be used in optoelectronic device sector. Unlike
the notable anisotropy found in elastic, mechanical properties and minimum
thermal conductivity, the optical parameters are found to be almost isotropic
with respect to the polarization direction of the incident electric field.
