Syntax:
pair_style hybrid/overlay ilp/graphene/hbn cutoff tap_flag
cutoff = global cutoff (distance units) tap_flag = 0/1 to turn off/on the taper function
Examples:
pair_style hybrid/overlay ilp/graphene/hbn 16.0 1 pair_coeff * * ilp/graphene/hbn BNCH.ILP B N C
pair_style hybrid/overlay rebo tersoff ilp/graphene/hbn 16.0 coul/shield 16.0 pair_coeff * * rebo CH.airebo NULL NULL C pair_coeff * * tersoff BNC.tersoff B N NULL pair_coeff * * ilp/graphene/hbn BNCH.ILP B N C
pair_coeff 1 1 coul/shield 0.70 pair_coeff 1 2 coul/shield 0.69498201415576216335 pair_coeff 2 2 coul/shield 0.69
Description:
The ilp/graphene/hbn style computes the registry-dependent interlayer potential (RDILP) potential as described in (Leven) and (Maaravi). The normals are calculated in the way as described in (Kolmogorov).
Where Tap(r_ij) is the taper function which provides a continuous cutoff (up to third derivative) for interatomic separations larger than r_c (Maaravi). The definitons of each parameter in the above equation can be found in (Leven) and (Maaravi).
It is important to include all the pairs to build the neighbor list for calculating the normals.
NOTE: This potential is intended for interactions between two different layers of graphene or hexagonal boron nitride. Therefore, to avoid interaction within the same layers, each layer should have a separate molecule id and is recommended to use "full" atom style in the data file.
The parameter file (e.g. BNCH.ILP), is intended for use with metal units, with energies in meV. Two additional parameters, S, and rcut are included in the parameter file. S is designed to facilitate scaling of energies. rcut is designed to build the neighbor list for calculating the normals for each atom pair.
NOTE: The parameters presented in the parameter file (e.g. BNCH.ILP), are fitted with taper function by setting the cutoff equal to 16.0 Angstrom. Using different cutoff or taper function should be careful.
NOTE: Two parameter files (BNCH.ILP and BNCH-old.ILP) are presented, BNCH-old.ILP contains the parameters published in (Leven) and (Maaravi), which is only suitable for long-range interaction. The parameters in BNCH.ILP provides a good description both for short- and long-range interaction. This is useful for simulations in the high pressure (small interlayer distances) regime. The comparison of two sets of parameters can be found in (Ouyang).
This potential must be used in combination with hybrid/overlay. Other interactions can be set to zero using pair_style none.
Mixing, shift, table, tail correction, restart, rRESPA info:
This pair style does not support the pair_modify mix, shift, table, and tail options.
This pair style does not write their information to binary restart files, since it is stored in potential files. Thus, you need to re-specify the pair_style and pair_coeff commands in an input script that reads a restart file.
Restrictions:
This fix is part of the USER-MISC package. It is only enabled if LAMMPS was built with that package. See the Making LAMMPS section for more info.
This pair potential requires the newton setting to be on for pair interactions.
The BNCH.ILP potential file provided with LAMMPS (see the potentials directory) are parameterized for metal units. You can use this potential with any LAMMPS units, but you would need to create your BNCH.ILP potential file with coefficients listed in the appropriate units, if your simulation does not use metal units.
Related commands:
pair_coeff pair_none pair_style hybrid/overlay pair_style pair_kolmogorov_crespi_z pair_style pair_kolmogorov_crespi_full pair_style pair_coul_shield
Default: tap_flag = 1
(Leven) I. Leven et al, J. Chem.Theory Comput. 12, 2896-905 (2016)
(Maaravi) T. Maaravi et al, J. Phys. Chem. C 121, 22826-22835 (2017).
(Kolmogorov) A. N. Kolmogorov, V. H. Crespi, Phys. Rev. B 71, 235415 (2005)
(Ouyang) W. Ouyang, D. Mandelli, O. Hod, M. Urbakh, In preparation.