[lammps-users] use of Stillinger-Weber

Hi Steve and Paul,

I want to thank you for adding the Stillinger-Weber potential to Lammps.

I have some elementary questions about the use of the sw potential and where is taking the parameters from:

  1. Does the program read the file.sw (e.g. si.sw) from its current direction in the potentials directory, or should I
    copy it and place it where the simulation is run?

  2. Wherever file.sw goes, I assume I can change the parameters and use without recompiling. Please let me know
    if I am wrong.

  3. If I have different atom types in the simulation, and all of them interact with the SW potential, should I indicate
    how the parameters are mixed? (for the two body part) or have to write explicit terms for all pair and triplets?

  4. Can I control the mass of the atoms independently? (e.g. have two silicon atoms with different parameters in
    same simulation box)

  5. in the manual example for pair_style sw, the " * *" in the example for the coefficient is really a star or the number
    of the potential? e.g. pair_coeff 1 1 si.sw Si

  6. I do not understand the example for 4 different atom types
    pair_coeff * * SiC.sw Si Si Si C
    are the three Si different in terms of atom types, with different parameters? Could you please send me this SiC.sw
    file as an example (with any parameters, I do not understand the structure).

  7. Is the sw ready to be used in combination with other potentials? if yes and you have a data (and input) file examples
    that you can make available, i will really appreciate it.

Thanks for your patience reading this and for the help you can provide me to get started with this,