nitrogen buffer gas point charge

[joegair]

Hello, I'm really enjoying using CoSIMS. The manuscript makes it sounds like it should be straightforward to use a point-charge model of N2 as a buffer gas. "Thus a point-particle model of nitrogen can also be used with this program, given the proper Lennard-Jones parameters and atomic polarizability." None of the options that I am seeing listed in the input file look like they are related to defining the buffer gas or the parameters of a buffer gas. Do these changes need to be made somewhere other than the input file?

[ChristopherAMyers]

Apologies for my late reply to this one!

If you use the atoms.dat file, you can change the Lennard-Jones parameters (sigma and epsilon).

See an example here
[And here the the atoms.dat file]
(https://github.com/ChristopherAMyers/CoSIMS/blob/master/examples/change_atom_type/atoms.dat)

The last part that might come into play is the polarizability of Nitrogen, which unlike Helium, will be anisotropic. We never explored how the CCS would be sensitive to this parameter, so only a point-like Nitrogen can be modeled with CoSIMS (so far).