virtual void add_energy(const Particle &p, const Utils::Vector3d &folded_pos, double time, Observable_stat &energy) const =0
Add constraint energy for particle to the energy observable.
virtual ParticleForce force(const Particle &p, const Utils::Vector3d &folded_pos, double time)=0
Calculate the force of the constraint on a particle.
Force information on a particle.
Struct holding all information for one particle.