A comprehensive DFT based insights into the physical properties of tetragonal Mo5PB2

Abstract: 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.