Investigation on Atomic Structure and Mechanical Property of Na- and Mg-Montmorillonite under High Pressure by First-Principles Calculations

Montmorillonite is an important layered phyllosilicate material with many useful physicochemical and mechanical properties, which widely used in medicine, environmental protection, construction industry, other fields. In order to a get better understanding of the behavior montmorillonite under high pressure, we studied its atomic structure, electronic properties using density functional theory (DFT), including dispersion corrections, as function interlayer Na Mg cations. At ideal condition, calculations lattice constants, bond length, band elastic modulus Na- Mg-montmorillonite are good agreement experimental values. Under constants major lengths decreased increasing pressure. The calculated structure show only slight change 20 GPa, indicating that effect pressure on weak. bulk modulus, shear Young’s wave velocity compression positively correlated external parameters have little change. studies will be explore experiments future from purely scientific point view.