First-principles study on the electronic structure and mechanical properties of palygorskite

To broaden the applications of palygorskite in the fields of materials science, it is significant to systematically explore the electronic structure and physicochemical properties of palygorskite through density-functional theory and generalized gradient approximation. Herein, the band structure, electronic density of states (DOS), and elastic constants of palygorskite single crystal are calculated via first-principles method. Theoretical studies confirm that the Mg-O bonds of palygorskite are longer and more flexible as compared to those of Si-O bonds. Moreover, the Mg-O bonds exhibits typical ionicity, while the Si-O bonds are more covalent. The subsequent band structure simulation results reveal that valence band maximum and conduction band minimum of palygorskite are all located at the G-point. And, the direct band gap of palygorskite is calculated to be 4.58 eV. Mechanical properties analysis demonstrates the excellent rigidity and outstanding elastic deformation resistance of palygorskite. Additionally, palygorskite exhibits limited ductility, which is characterized by a high Young's modulus and low shear modulus. The in-depth understanding of the electronic structure and mechanical properties of palygorskite provides valuable theoretical guidance for its application in materials science.