Contents |
Potential Types
This table contains information about the potentials use in MD++.
| Name of Potential | executable | Types of Materials |
|---|---|---|
| Molecular Dynamics | md_$(SYS) | empty potential, for visualization and atom manipulation |
| Finnis-Sinclair | fs_$(SYS) | BCC metals (Mo, Ta, W, ...) |
| Embedded Atom Method | eam_$(SYS) | FCC metals (Cu, Au, ...) |
| Aluminum Glue | alglue_$(SYS) | Al (FCC metal) |
| Modified Embedded Atom Method | meam_$(SYS) | FCC metals, BCC metals, semiconductors |
| Lennard-Jones | lj_$(SYS) | Noble gas (Ar, ...) |
| Stillinger-Webber | sw_$(SYS) | Semiconductors (Si, Ge, C) |
| Tersoff | tersoff_$(SYS) | Semiconductors (Si, Ge, C), PRB 39 5566 (1989) |
| Tersoff88 | tersoff88_$(SYS) | Si(B) - PRB 37 6991 (1988), Si(C) - PRB 38 9902 (1988) In default, the parameters are set to Si(C). The parameters can be reset to Si(B) by modifying source code, "tersoff88.cpp". |
| Brenner | brenner_$(SYS) | C, hydrocarbons |
Relation between the parameters in SW potential and in MD++ codes
The parameters in SW potential model and in MD++ codes are associated, following the rules described in table below. When changing values of the parameters in MD++ codes, make sure you know what you are changing and how.
| Parameters in Balamane et al (PRB 46 2250) | Parameters in original SW (PRB 31 5262) | Variables in MD++ |
|---|---|---|
| A_1 | = ε*A*B*σ^p | bb = A_1/aa = B*σ^(p-q) |
| A_2 | = ε*A*σ^q | = aa |
| Z | = ε*λ | = plam |
| μ | = σ | = pss |
| α | = γ | pgam = γ*pss |
| R_c | = a*σ | = acut |
| λ_1 | = p | = rho |
| λ_2 | = q | Not Used (0) |
"Potential" Problems
These are some potential files we used in our simulations of molecular structures. Please note that since we use a variety of codes, the potential files will be in a variety of formats. The most common codes used by our group are LAMMPS ( and ParaDyne) and MD++. These codes use different file formats for EAM potentials, so all files should specify which file format. We will also try to provide a reference describing the potential.
Potential Files
MD++ Files
EAM Foiles potential for Gold. Ref: Park, H. S., Zimmerman J. A., Modeling inelasticity and failure in gold nanowires. Phys. Rev. B 72, 054106 (2005).
EAM Foiles potential for Copper. Ref: Aubry, S. and Hughes, D. A., Reductions in stacking fault widths in fcc crystals: Semiempirical calculations. Phys. Rev. B 73, 224116 (2006).
LAMMPS SET Files
EAM Foiles potential for Copper. Ref: Aubry, S. and Hughes, D. A., Reductions in stacking fault widths in fcc crystals: Semiempirical calculations. Phys. Rev. B 73, 224116 (2006).