Linearly truncated Lennard-Jones potential¶
This module implements the Lennard-Jones potential with a linear truncation scheme (which is equivalent to a shifted force),
for the interaction between two particles of species and
. Here,
denotes the cutoff distance and
the force at the cutoff for the untruncated potential.
This linear truncation scheme modifies the potential drastically and at all
distances by adding a constant force, and we do not recommend it for future
work. It is mainly provided for historical reasons to connect to existing
data and publications. Please refer to the local r⁴ truncation
scheme for an alternative.
References¶
- S. K. Das, J. Horbach, K. Binder, M. E. Fisher, and J. V. Sengers, J. Chem. Phys. 125, 024506 (2006)
- S. Toxvaerd and J. C. Dyre, J. Chem. Phys. 134, 081102 (2011)
- S. Toxvaerd, O. J. Heilmann, and J. C. Dyre, J. Chem. Phys. 136, 224106 (2012)
-
class
halmd.mdsim.potentials.pair.
lennard_jones_linear
(args)¶ Construct linearly truncated Lennard-Jones potential.
Parameters: - args (table) – keyword arguments
- args.epsilon (table) – matrix with elements
(default:
1
) - args.sigma (table) – matrix with elements
(default:
1
) - args.cutoff (table) – matrix with elements
- 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.Note
The cutoff is only relevant with
halmd.mdsim.forces.pair_trunc
.-
epsilon
¶ Matrix with elements
.
-
sigma
¶ Matrix with elements
.
-
r_cut
¶ Matrix with elements
in reduced units.
-
r_cut_sigma
¶ Matrix with elements
in units of
.
-
description
¶ Name of potential for profiler.
-
memory
¶ Device where the particle memory resides.