CLAYFF in LAMMPS

Dear all,

I am trying to simulate an Alumina-Water system using CLAYFF in LAMMPS. I have read through the previous discussion in this forum about implementing CLAYFF in LAMMPS. I just to confirm that I could use the standard 12-6 L-J potential in LAMMPS to simulate the van der Waals part of CLAYFF.

In CLAYFF, the van der Waals part is simulated with a L-J potenail formulated with two parameters: the depth of the potential well (epsilon), and the the distance where the potential reaches its minimum (rm). In LAMMPS, the standard 12-6 L-J potential is formulated with two parameters: the depth of the potential well (epsilon), and the the distance where the potential is zero (sigma). And the relation between rm and sigma is rm = 2^(1/6) * sigma. The CLAYFF potentil gives the epsilon and rm for the L-J potential between different types of atoms. Thus, by calculating sigma from the given rm using the relation “rm = 2^(1/6) * sigma”, the van der Waals part of the CLAYFF potential could be simulated with the standard 12-6 L-J potential in LAMMPS with the given epsilon and calculated sigma. I wonder whether this is correct. Thanks a lot for your time and help!

Bests,

Han Hu

Complex Fluids and Multiphase Transport Lab
Mechanical Engineering and Mechanics Department
Drexel University
Hess Engineering Research Laboratories
hh398@…1685…, edenkira@…24…

yes, what you say sounds right - you can ask Jeff Greathouse (CCd)

who knows more about CLAYFF and LAMMPS.

Steve

Hi Steve,

Thanks a lot.

Hi Jeffery,

I was wondering whether you could give your opinion on whether the van der Waals part of CLAYFF could be simulated with the standard 12-6 L-J potential in LAMMPS? I appreciate your help and time very much.