Lennard-Jones potential¶
This module implements the Lennard-Jones potential,
for the interaction between two particles of species \(i\) and \(j\).
- class halmd.mdsim.potentials.pair.lennard_jones(args)¶
Construct Lennard-Jones potential.
- Parameters:
args (table) – keyword arguments
args.epsilon (table) – matrix with elements \(\epsilon_{ij}\) (default:
1
)args.sigma (table) – matrix with elements \(\sigma_{ij}\) (default:
1
)args.species (number) – number of particle species (optional)
args.memory (string) – select memory location (optional)
args.label (string) – instance label (optional)
If the argument
species
is omitted, it is inferred from the first dimension of the parameter matrices.If all elements of a matrix are equal, a scalar value may be passed instead which is promoted to a square matrix of size given by the number of particle
species
.The supported values for
memory
are “host” and “gpu”. Ifmemory
is not specified, the memory location is selected according to the compute device.- epsilon¶
Matrix with elements \(\epsilon_{ij}\).
- sigma¶
Matrix with elements \(\sigma_{ij}\).
- r_cut¶
Matrix with elements \(r_{\text{c}, ij}\) in reduced units.
- r_cut_sigma¶
Matrix with elements \(r_{\text{c}, ij}\) in units of \(\sigma_{ij}\).
- description¶
Name of potential for profiler.
- memory¶
Device where the particle memory resides.
- truncate(args)¶
Truncate potential. See Potential truncations for available truncations.
- Parameters:
args (table) – keyword argument
args[1] (string) – name of truncation type
cutoff (table) – matrix with elements \(r_{\text{c}, ij}\)
args.* (any) – additional arguments depend on the truncation type
- Returns:
truncated potential
Example:
potential = potential:truncate({"smooth_r4", cutoff = 5, h = 0.05})
- modify(args)¶
Apply potential modification. See Potential modifications for available modifications.
- Parameters:
args (table) – keyword argument
args[1] (string) – name of modification type
args.* (any) – additional arguments depend on the modification type
- Returns:
modified potential
Example:
potential = potential:modify({"hard_core", radius = 0.5})