DebyeHückel

DebyeHückelPotential #

It is a electrostatic potential in an ionic solution based on Debye-Hückel equation.

\[U(r_{ij}) = \frac{q_i q_j}{4\pi\epsilon_0\epsilon_k r_{ij}} \exp(-r_{ij}/\lambda_D)\] \[\lambda_D = \sqrt{\frac{\epsilon_0\epsilon_k}{2\beta N_A e_c^2 I}}\]

The permittivity of the water is derived from the same equation used in the following papers.

  • Sambriski, E. J. et al., (2009) Biophys. J.
  • Hinckley, D. M. et al., (2013) JCP.
  • Freeman, G. S., et al., (2014) JCP.

Example #

[[forcefields.global]]
interaction = "Pair"
potential   = "DebyeHuckel"
ignore.particles_within.bond = 3
spatial_partition.type = "CellList"
spatial_partition.margin = 0.2
cutoff     = 5.5
parameters = [
    {index = 0, charge = 1.0},
]

Input Reference #

This potential requires system attribute, temperature and ionic_strength.

  • cutoff: Floating (Optional. By default, 5.5.)
    • Cutoff length relative to the debye length.
  • index: Integer
    • The index of the particle.
  • offset: Integer (ptional. By default, 0.)
    • Offset value of the index.
  • charge: Floating
    • The value of charge of the particle.