LAMMPS calculation were done using MPinterfaces code with minor modification (https://github.com/henniggroup/MPInterfaces/blob/master/examples/workflows/lammps_workflow.py) and in.elastic script in LAMMPS/examples/ELASTIC folder (https://github.com/lammps/lammps/tree/master/examples/ELASTIC) on the structures downloaded from materials project (MP) using REST API (https://www.materialsproject.org/).Force-fields were downloaded from interatomic potential repository project(http://www.ctcms.nist.gov/potentials/) and LAMMPS (https://github.com/lammps/lammps/tree/master/potentials). The interactive plot was made with Bokeh (http://bokeh.pydata.org/en/0.10.0/docs/gallery/periodic.html). The starting lattice parameters were taken from density functional theory (DFT) and not from experiments. Generic minimization parameters were chosen for LAMMPS run rather than testing them for each individual case such as energy convergence criterion and so on. Hence, there are chances that the calculation gets trapped in a local energy minima. Please read carefully the assumptions taken during calculations in the in.elastic script and use the data at your own risk !


HINT: Typically any force-field based calculation with density functional theory based energy above convex hull (E_hull_mp) = 0 (stable structure) should have reasonable cohesive energy (EN/atom) and non-negative elastic constants (dynamically stable). Corresponding DFT based elastic constnat and cohesive energy data data should be available by clicking the mp-* value. .

How to use

Enter element A, A-B, A-B-C in the SEARCH box and hit enter or click A, A+SHIFT+B, A+SHIFT+B+SHIFT+C in the periodic table. To refresh a selection press Esc or F5. The periodic table, the header and the datatable are re-sizable on drag. After element(s) selection, click on Calc-* or Force-fields* to download zip files for the calc. Click mp-* to go to Materials project (MP) data such as visualization of structure, and electronic properties.

The Calc-* folder contains the input files for directly running lammps with in.elastic (for user-verification) and the log.lammps (output file). The restart file can be used for running subsequent calculations such as for defects and phonons. User will have to adjust the path of force-fileds inside potential.mod file to run the calculation on a local machine. All the data presented here and 21 distinct elastic constants are in the Calc-* folder (log.lammps file) and would be available with REST API soon.

For any technical question, email kamal.choudhary@nist.gov.

Available options

MONOATOMIC: Ag, Al, Au, B, Br, C, Cd, Cl, Co, Cr, Cs, Cu, F, Fe, Ga, Ge, H, Hf, Hg, K, Li, Mg, Mo, N, Na, Nb, Ni, O, P, Pb, Pd, Pt, Rb, Ru, S, Se, Si, Sm, Ta, Te, Ti, U, V, W, Xe, Zn, Zr.

BINARIES: Ag-Cu, Ag-Pd, Al-Co, Al-Cu, Al-Fe, Al-H, Al-Mg, Al-Nb, Al-Ni, Al-O Al-Sm, Al-Ti, B-C, B-N, Br-Cl, Br-Cs, Br-F, Br-K, Br-Li, Br-Na, Br-Rb, C-Fe, C-H, C-N, C-O C-V, Cd-Hg, Cd-S, Cd-Se, Cd-Te, Cd-Zn, Cl-Cs, Cl-F, Cl-K, Cl-Li, Cl-Na, Cl-Rb, Cr-Ni, Cs-F, Cs-K, Cs-Rb, Cu-H, Cu-O, Cu-Si, Cu-Ti, Cu-Zr, F-K, F-Li, F-Na Fe-H, Fe-Ni, Fe-O, Fe-P, Fe-V, Ga-N, H-N, H-Ni, H-O, H-Pd, H-Zn, H-Zr, Hf-O, Hf-Si, Hg-S, Hg-Se, Hg-Te, Hg-Zn, K-Na, K-Rb, Li-Na, Li-Rb, Mo-U, N-O Nb-Ti, Ni-Zr, O-Si, O-Ti, O-V, O-Zn, O-Zr, S-Se, S-Zn, Se-Zn, Te-Zn.

TERNARIES: B-C-N, Br-Cs-F, Br-Cs-Li, Br-F-K, Br-F-Rb, Br-Li-Rb, C-Cu-O, C-Fe-O, C-H-N, C-H-O, C-O-V, Cd-S-Zn, Cd-Te-Zn, Cl-Cs-Li Cs-F-Li, Cu-H-O, Cu-O-Si, Cu-O-Ti, F-Li-Rb, Fe-H-O, H-N-O, H-O-V, H-O-Zn.