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OPLS bending

Description

The opls_bend type of bending potential calculates the bending potential associated to the OPLS force field:

\[ E = k \left ( \theta -\theta_0 \right )^2 \]

with \(k\) and \(\theta_0\) the potential parameters decribed in the following table.

Parameter Units Description
\(k\) energy force constant
\(\theta_0\) angle equilibrium bending angle

YAML syntax

compute_force_bend:
  potentials_for_bends:
    - types: [STRING, STRING, STRING]
      potential: opls_bend
      parameters:
        theta0: VALUE UNITS
        k: VALUE UNITS
  • STRING = Name of the atom type (specie) involved in the bending angle.
  • VALUE = Physical value of the intended parameter.
  • UNITS = Units of the provided value that will be passed to the conversion helper for internal units conversion.

Usage examples

Systems with a single atom type (specie)

compute_force_bend:
  potentials_for_bends:
    - types: [CA, CA, CA]
      potential: opls_bend
      parameters:
        theta0: 1.200000e+02 degree
        k: 4.3799765e-19 J

Systems with several atom types (species)

compute_force_bond:
  potentials_for_bonds:
    - types: [CA, CA]
      potential: opls_bond
      parameters:
        r0: 1.400000e-10 m
        k: 4.3799765e-19 J/m^2
    - types: [CA, CA, CR4]
      potential: opls_bond
      parameters:
        theta0: 1.200000e+02 degree
        k: 4.8666405e-19 J