First principles study of electronic, bonding, elastic properties and intrinsic hardness of CdSiP2

CdSiP2 is regarded to be a promising material for future technical applications, but many of its properties are still not well studied. In this work, electronic, bonding, elastic properties and intrinsic hardness of CdSiP2 are investigated by performing first principles calculations within the framework of generalized gradient approximation. Calculations indicate that CdSiP2 is a direct-gap semiconductor with a gap value of 1.22 eV located at the Γ-point. Combined with the density of states, the characteristics of the band structure have been analyzed and their origins have been specified, which reveal that sp3 hybridization plays an important role in the formation of the crystal. Charge analyses disclose that CdSiP2 is a crystal with ionic and covalent properties. The calculated intrinsic hardness of CdSiP2 is 10.05 GPa, agreeing well with the experimental value of 10.5 GPa. Its bulk modulus and elastic constants, together with its elastic anisotropy, are also computed and analyzed. The obtained elastic constants are larger than other theoretical ones, as a result, the bulk modulus deduced gives a value of 80.99 GPa, which is more reasonable compared with the experimentally derived value and other theoretical ones.