Hi,
I’m trying to learn the process behind determining the Tersoff parameters of 8 entries (SiSiSi, SiSiC, SiCSi, SiCC, CSiSi, CSiC, CCSi, CCC) for a two-element simulations in LAMMPS. These entries are derived from the parameters provided for Si-C, Si-Si, and C-C interactions. Based on the LAMMPS documentation, the parameters used for the two-body interaction come from the entry where the second element is repeated. Thus, the two-body parameters for Si interacting with C, comes from the SiCC entry. The parameters used only for two-body interactions in entries whose second and third element are different (e.g. SiCSi) are not used for anything and can be set to 0.0 if desired. How about the parameters used for three-body interactions, i.e. (lambda3, gamma, c, d, h)? Where do they com form in each of the mentioned cases (e.g. for the entry where the second element is repeated)? The manual says parameters used for a particular three-body interaction come from the entry with the corresponding three elements. What does it mean exactly?
I would greatly appreciate any advice or insights you can provide on this matter.