About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
First-principles Calculation of the Pressure Derivative of the Bulk Modulus from Second- and Third-order Elastic Constants |
Author(s) |
Angelo Bongiorno |
On-Site Speaker (Planned) |
Angelo Bongiorno |
Abstract Scope |
A first principles method is presented to calculate the bulk modulus and its pressure derivative of a material in an arbitrary stressed state. The bulk modulus is obtained from the compliance Birch tensor, whereas its pressure derivative is calculated numerically within a nonlinear elasticity theory framework by using second- and third-order elastic constants obtained from density functional theory calculations. To demonstrate validity, generality, and accuracy, this approach is used to calculate bulk modulus and its pressure derivative of silicon and quartz over finite intervals of the hydrostatic pressure, and of sodium chloride at zero hydrostatic pressure and incremental differential stress. To demonstrate impact, the method is also used to elucidate the origin of the unusual elastic softening under hydrostatic compression (i.e. negative value of the pressure derivative of the bulk modulus) exhibited by monoclinic hafnia and amorphous silica. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Mechanical Properties, Modeling and Simulation |