Hybrid potential stencil issue

LAMMPS LAMMPS General Discussion
1

Hi all,
I am constructing some simulations with mixed SiC and Graphene components by combining meam/c, bop and lj/cut pair styles. Details of the hybrid style are below.

Si C H C

pair_style hybrid meam/c bop save lj/cut 5.14227 lj/cut 6.39754 lj/cut 6.00198 lj/cut 6.00198 lj/cut 7.2572 lj/cut 6.8617
pair_coeff * * meam/c library.meam Si C SiC.meam Si C NULL NULL
pair_coeff * * bop CCu_v2.bop.table NULL NULL NULL C
pair_coeff 3 3 lj/cut 1 0.00190797 2.57113
pair_coeff 1 3 lj/cut 2 0.00576712 3.19877
pair_coeff 2 3 lj/cut 3 0.00294741 3.00099
pair_coeff 3 4 lj/cut 4 0.00294741 3.00099
pair_coeff 1 4 lj/cut 5 0.00890896 3.6286
pair_coeff 2 4 lj/cut 6 0.00455312 3.43085

Neighbor

neighbor 1.0 multi/old
neigh_modify once no every 5 delay 0 check no

BOP Comm Requirement

comm_modify mode multi/old cutoff/multi/old 4*4 12.0

LAMMPS seems to be fine with the parameter setup, but as soon it starts running, it reports this error.

ERROR: Requested neighbor stencil method does not exist (src/neighbor.cpp:900)

The documentation on this error seems sparse, does anyone have any experience with it? It could be entirely possible I just missed a simple setting in the hybrid potential.

2

Try without multi-cutoff neighborlist build and communication. Or with the new version.

3

After a little debugging and testing, I have to advise you that pair style bop is neither compatible with being used with pair style hybrid, nor is it compatible with multi cutoff neighbor lists.
Future versions of LAMMPS will contain checks for that and will terminate with a suitable error message.

4

Please also note that it is not necessary to have six different lj/cut sub-styles, a single one is sufficient, since you can specify the cutoff for each pair_coeff statement individually. E.g. like this:

pair_style hybrid meam/c bop save lj/cut 5.14227
pair_coeff * * meam/c library.meam Si C SiC.meam Si C NULL NULL
pair_coeff * * bop CCu_v2.bop.table NULL NULL NULL C
pair_coeff 3 3 lj/cut  0.00190797 2.57113 5.14227
pair_coeff 1 3 lj/cut  0.00576712 3.19877 6.39754
pair_coeff 2 3 lj/cut  0.00294741 3.00099 6.00198
pair_coeff 3 4 lj/cut  0.00294741 3.00099 6.00198
pair_coeff 1 4 lj/cut  0.00890896 3.6286 7.2572
pair_coeff 2 4 lj/cut  0.00455312 3.43085 6.8617