Trait TorsionKernel 

pub trait TorsionKernel<T: Real> {
    type Params: Copy;

    // Required methods
    fn energy(cos_phi: T, sin_phi: T, params: Self::Params) -> T;
    fn diff(cos_phi: T, sin_phi: T, params: Self::Params) -> T;
    fn compute(cos_phi: T, sin_phi: T, params: Self::Params) -> EnergyDiff<T>;
}

Trait for torsional potentials (Dihedrals).

Models interaction energy as a function of the dihedral angle $\phi$.

Mathematical Contract

• Input: Both $\cos\phi$ and $\sin\phi$ are required to determine phase and compute multi-term expansions (e.g., $\cos(n\phi)$) without acos.
• Output (Diff): The pure torque $T$ defined as: $$ T = \frac{dE}{d\phi} $$

Required Associated Types

type Params: Copy

Associated constants/parameters required by the potential (e.g., $V, n$).

Required Methods

fn energy(cos_phi: T, sin_phi: T, params: Self::Params) -> T

Computes only the potential energy.

fn diff(cos_phi: T, sin_phi: T, params: Self::Params) -> T

Computes only the pure torque $T$.

fn compute(cos_phi: T, sin_phi: T, params: Self::Params) -> EnergyDiff<T>

Computes both energy and pure torque efficiently. Should share intermediate calculations where possible.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T: Real> TorsionKernel<T> for Torsion

type Params = (T, u8, T, T)