angle_style gaussian command

Syntax

angle_style gaussian

Examples

angle_style gaussian
angle_coeff 1 300.0 2 0.0128 0.375 80.0 0.0730 0.148 123.0

Description

The gaussian angle style uses the potential:

E = - k_{B} T l n (\sum_{i = 1}^{n} \frac{A_{i}}{w_{i} \sqrt{π / 2}} e x p (\frac{- 2 (θ - θ_{i})^{2}}{w_{i}^{2}}))

This analytical form is a suitable potential for obtaining mesoscale effective force fields which can reproduce target atomistic distributions (Milano).

The following coefficients must be defined for each angle type via the angle_coeff command as in the example above, or in the data file or restart files read by the read_data or read_restart commands:

$T$ temperature at which the potential was derived
$n$ (integer >=1)
$A_{1}$ (> 0, radians)
$w_{1}$ (> 0, radians)
$θ_{1}$ (degrees)
…
$A_{n}$ (> 0, radians)
$w_{n}$ (> 0, radians)
$θ_{n}$ (degrees)

Restrictions

This angle style can only be used if LAMMPS was built with the EXTRA-MOLECULE package. See the Build package doc page for more info.

Default

none

(Milano) G. Milano, S. Goudeau, F. Mueller-Plathe, J. Polym. Sci. B Polym. Phys. 43, 871 (2005).