Dear LAMMPS users,
I have separately equilibrated systems with hexagonal and diamond crystal structures. The hexagonal structure is an alloy consisting of 2 atoms. The diamond crystal structure is silicon. I would like to bond one of the atoms from this alloy at the interface to the Si atoms. I am using the Tersoff potential for creating both these structures.
Could someone let me know how I should go about doing this?
Thanks,
Mihir.
Dear Mihir, if you are treating the whole system with Tersoff, you dont need to worry about bonds as Tersoff is treated as pair_style in LAMMPS.
If you want to make bonds (with some other potential, harmonic or anything else for that matter), you can do that by adding bonds manually in datafile and updating the input script subsequently for bond_style, and other interactions.
Vikas
Hi,
On this specific note, what would the advantage/disadvantage be in bonding one of the atoms to Si using a L-J potential? Thereby using the hybrid potential option with Tersoff for describing Si and L-J for the interaction between one of the alloy atoms and Si.
Best regard,
CD
Vikas Varshney wrote:
Hi,
On this specific note, what would the advantage/disadvantage be in
to be able to only use tersoff, you need _all_ combinations of cross
terms (two-body and three-body) for _all_ atom types.
bonding one of the atoms to Si using a L-J potential? Thereby using the
hybrid potential option with Tersoff for describing Si and L-J for the
interaction between one of the alloy atoms and Si.
it all depends on what kind of interaction you _really_ have between
the two groups of atoms and how accurate you intend to model it.
when you don't know the interactions, option one is to search the
literature whether somebody has already looks at a similar system
and use whatever was done there, if it is applicable, option two
is to run an ab initio calculation (can be _very_ slow), option
three is to derive/parametrize a potential, which requires some
experience and more reading of related literature.
HTH,
axel.