BALL::CharmmImproperTorsion Class Reference
[CHARMM Force Field.]

#include <BALL/MOLMEC/CHARMM/charmmImproperTorsion.h>

Inheritance diagram for BALL::CharmmImproperTorsion:

Public Member Functions
Constructors and Destructors

	CharmmImproperTorsion ()
	CharmmImproperTorsion (ForceField &force_field)
	CharmmImproperTorsion (const CharmmImproperTorsion &charmm_stretch)
virtual	~CharmmImproperTorsion ()
Setup Methods

virtual bool	setup () throw (Exception::TooManyErrors)
Accessors

virtual double	updateEnergy ()
virtual void	updateForces ()
Private Attributes
vector < QuadraticImproperTorsion::Data >	impropers_
QuadraticImproperTorsion	improper_parameters_
ResidueTorsions	improper_atoms_

Detailed Description

Charmm improper torsion component. The CHARMM force field employs a harmonic out-of-plane potential for improper torsions. An imporper torsion is defined for four atoms A , B , C , and D where A is the central atom B , C , and D are bound to.

: The out-of-plane-angle phi is defined as the angle between the planes defined by ABC and BCD . The improper torsion energy $E_{imp}$ is then defined as $ E_{imp} = k ( - )^2 $ where $k$ and $$ are constants read from the parameter section and depend on the atom types of A , B , C , and D .