[lammps-users] Pair Hybrid EAM and Tersoff (or REBO) scripts


I want to run a simulation containing carbon nanotubes and iron using, EAM, Tersoff and LJ for Fe-Fe,C-C and Fe-C interactions respectively. LAMMPS documentation indicates the grammar should permit the following:

pair_style hybrid eam/fs lj/cut tersoff
pair_coeff 1 1 eam/fs Fe_mm.eam.fs Fe Fe
pair_coeff 1 2 lj/cut 0.00759200 3.5 9.7625
pair_coeff 2 2 tersoff C.tersoff C C

where Fe is atom type 1, C is atom type 2. This results in error (see * below)

I'd be grateful for any advice or a 2-4 line script segment that is proven to work for EAM and Tersoff.


Nicholas J. Lee

* I continue to experiment with the syntax from the LAMMPS documentation. Other modifications I have tried that also result in error include

replacing 1 1 (or 2 2) with * *. Even though I only want EAM between atom of type 1
removing tersoff from the 4th line - Line 1 of examples http://lammps.sandia.gov/doc/pair_tersoff.html
removing eam/fs from the 2nd line - Line 8 of examples http://lammps.sandia.gov/doc/pair_eam.html
specifying pair styles/coeff separately for FeFe and CC as if they were separate simulations

In case you need more information, I have attached an error log.

error log.txt (5.52 KB)

This set of lines works:

lattice fcc 0.8442
region box block 0 10 0 10 0 10
create_box 2 box

pair_style hybrid eam/fs lj/cut 10.0 tersoff
pair_coeff * * eam/fs ../potentials/Fe_mm.eam.fs Fe NULL
pair_coeff 1 2 lj/cut 0.00759200 3.5 9.7625
pair_coeff * * tersoff ../potentials/Si.tersoff NULL Si