sarkas.potentials.lennardjones.lj_force#

sarkas.potentials.lennardjones.lj_force(r_in, pot_matrix)[source]#

Numba’d function to calculate the PP force between particles using Lennard-Jones Potential.

Parameters

  • r_in (float) – Particles’ distance.

  • pot_matrix (numpy.ndarray) – LJ potential parameters.

    Shape = (5, sarkas.core.Parameters.num_species, sarkas.core.Parameters.num_species)

Returns

  • u_r (float) – Potential.

  • f_r (float) – Force.

Examples

>>> pot_const = 4.0 * 1.656e-21 # 4*epsilon in [J] (mks units)
>>> sigma = 3.4e-10   # [m] (mks units)
>>> high_pow, low_pow = 12., 6.
>>> short_cutoff = 0.0001 * sigma
>>> pot_mat = array([pot_const, sigma, high_pow, low_pow, short_cutoff])
>>> r = 15.0 * sigma  # particles' distance in [m]
>>> lj_force(r, pot_mat)
(-5.815308131440668e-28, -6.841538377536503e-19)