Module lumol::energy

Interaction potentials for energy and forces computations

Potentials

In classical simulations, the total energy of a system is separated as a sum containing terms from the non-bonded pairs, the bonds, the angles, the dihedral angles in the system; and the electrostatic interactions.

Potentials are used to compute the interaction energy in a system. They are represented by a Potential trait, used to compute the force and the energy of interaction. In order to add a new potential to lumol, one has to implement the Potential trait, and then indicate how the potential can be used. This is done by implementing one or more of the potentials marker traits:

• PairPotential for non-bonded two body interactions;
• BondPotential for covalent bonds interactions;
• AnglePotential for covalent angles interactions;
• DihedralPotential for covalent dihedral angles interactions.

use lumol_core::energy::{Potential, PairPotential, DihedralPotential};

#[derive(Clone)]
struct OnePotential;

// OnePotential is a potential
impl Potential for OnePotential {
    fn energy(&self, _: f64) -> f64 {1.0}
    fn force(&self, _: f64) -> f64 {0.0}
}

// It can be used for pair and dihedral potentials, but not for angles or
// bonds.
impl PairPotential for OnePotential {
    /* some code omitted */
}
impl DihedralPotential for OnePotential {}

Global and Coulombic potentials

Global potentials are potentials that have an effect on the whole system at once. They are defined by implementing the GlobalPotential GlobalPotential trait. CoulombicPotential are a specific version of global potentials used to compute electrostatic interactions.

Structs

BornMayerHuggins	Born-Mayer-Huggins potential.
Buckingham	Buckingham potential.
CosineHarmonic	Cosine harmonic potential.
Ewald	Ewald summation for coulombic interactions.
Gaussian	Gaussian potential.
Harmonic	Harmonic potential.
LennardJones	Lennard-Jones potential.
Mie	Mie potential.
Morse	Morse potential
NullPotential	No-op potential.
PairInteraction	A non-bonded interaction between two particle.
RestrictionInfo	Restriction information attached to a pair of Particles in a System.
SharedEwald	Thread-sade wrapper around Ewald implementing CoulombicPotential.
TableComputation	Computation of a potential using tabulated values.
Torsion	Torsion potential.
Wolf	Wolf summation for coulombic interactions.

Enums

BondPath	Shortest bond path between two particles in a system
PairRestriction	Possible restrictions on the pair interactions.

Traits

AnglePotential	Marker trait for potentials that can be used for molecular angles.
BondPotential	Marker trait for potentials that can be used for molecular bonds.
Computation	Alternative energy and forces computation.
CoulombicPotential	Electrostatic potential solver.
DihedralPotential	Marker trait for potentials that can be used for molecular dihedral angles.
GlobalCache	Energetic cache for global potentials.
GlobalPotential	A potential acting on the whole System at once.
PairPotential	Marker trait for potentials that can be used for non-bonded two body interactions.
Potential	A potential for force and energy computations.