About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
Algorithm Development in Materials Science and Engineering
|
Presentation Title |
Recent Interatomic Potential Development Activities at Sandia |
Author(s) |
Xiaowang Zhou |
On-Site Speaker (Planned) |
Xiaowang Zhou |
Abstract Scope |
Sandia is performing molecular-dynamics studies of two hydrogen-storage material problems: helium bubble growth in palladium tritides, and thermodynamics of Mg-B-H systems. To enable helium bubble growth simulations, the Pd-T-He interatomic potential must address two paradoxes: He is repulsive in He but attractive in Pd, and He has a small diffusion barrier but a large swelling in Pd. We have developed a Finnis-Sinclair type of Pd-T-He embedded-atom method potential to overcome both paradoxes. Preliminary molecular-dynamics simulations reveal not only He-bubble nucleation, but also fast He-cluster diffusion that was later verified by our density-function-theory calculations. Mg-B-H systems contain many molecules in amorphous forms, which cannot be modeled by conventional interatomic potentials. We have developed a molecular Mg-B-H force field where molecules are stabilized by intra-molecule potentials and interaction energy between molecules is correctly captured by pairwise inter-molecule potentials. This approach has been implemented in LAMMPS and successful simulations have been demonstrated. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |