LJGauss¶

class hoomd.md.pair.LJGauss(nlist, default_r_cut=None, default_r_on=0.0, mode='none')¶

Lennard-Jones-Gauss pair potential.

Parameters:

nlist (hoomd.md.nlist.NeighborList) – Neighbor list.
default_r_cut (float) – Default cutoff radius \([\mathrm{length}]\).
default_r_on (float) – Default turn-on radius \([\mathrm{length}]\).
mode (str) – Energy shifting/smoothing mode.

LJGauss computes the Lennard-Jones Gauss force on all particles in the simulation state:

\[U(r) = 1\ [\mathrm{energy}] \cdot \left[ \left ( \frac{1\ [\mathrm{length}]}{r} \right)^{12} - 2\ \left(\frac{1 [\mathrm{length}]}{r} \right)^{6} \right] - \epsilon \exp \left[- \frac{\left(r - r_{0}\right)^{2}}{2 \sigma^{2}} \right]\]

Example:

nl = hoomd.md.nlist.Cell()
ljg = pair.LJGauss(nl)
ljg.params[("A", "A")] = dict(epsilon=1.0, sigma=0.02, r0=1.6)
ljg.params[("A", "B")] = {
    "epsilon": 2.0,
    "sigma": 0.02,
    "r0": 1.6,
}
ljg.params[("A", "B")] = {
    "epsilon": 2.0,
    "sigma": 0.02,
    "r0": 1.6,
}

Members inherited from AutotunedObject:

property kernel_parameters¶: Kernel parameters. Read more...

property is_tuning_complete¶: Check if kernel parameter tuning is complete. Read more...

tune_kernel_parameters()¶: Start tuning kernel parameters. Read more...

Members inherited from Force:

additional_energy¶: Additional energy term. Read more...

additional_virial¶: Additional virial tensor term \(W_\mathrm{additional}\). Read more...

cpu_local_force_arrays¶: Local force arrays on the CPU. Read more...

energies¶: Energy contribution \(U_i\) from each particle. Read more...

energy¶: The potential energy \(U\) of the system from this force. Read more...

forces¶: The force \(\vec{F}_i\) applied to each particle. Read more...

gpu_local_force_arrays¶: Local force arrays on the GPU. Read more...

torques¶: The torque \(\vec{\tau}_i\) applied to each particle. Read more...

virials¶: Virial tensor contribution \(W_i\) from each particle. Read more...

Members inherited from Pair:

nlist¶: Neighbor list used to compute the pair force. Read more...

mode¶: Energy smoothing/cutoff mode. Read more...

r_cut¶: Cuttoff radius beyond which the energy and force are 0. Read more...

r_on¶: Radius at which the XPLOR smoothing function starts. Read more...

compute_energy()¶: Compute the energy between two sets of particles. Read more...

Members defined in TWF:

params¶

The potential parameters. The dictionary has the following keys:

epsilon (float, required) - energy parameter \(\varepsilon\) \([\mathrm{energy}]\)
sigma (float, required) - Gaussian width \(\sigma > 0\) \([\mathrm{length}]\)
r0 (float, required) - Gaussian center \(r_0\) \([\mathrm{length}]\)