Struct Buck 

pub struct Buck<T> { /* private fields */ }

Buckingham (Exp-6) potential.

Parameters

• a: Repulsion amplitude (energy units)
• b: Repulsion steepness (1/length units)
• c: Dispersion coefficient (energy * length^6 units)

Precomputed Values

• neg_b: Stores -b internally for efficient exp(-b*r) computation

Implementations

impl<T: Vector> Buck<T>

pub fn new(a: f64, b: f64, c: f64) -> Self

Creates a new Buckingham potential.

Arguments

• a: Repulsion amplitude (energy units)
• b: Repulsion steepness (1/length units)
• c: Dispersion coefficient (energy * length^6 units)

Example

use potentials::pair::Buck;

// NaCl parameters (example values)
let buck = Buck::<f64>::new(1000.0, 3.0, 100.0);

pub fn from_rho(a: f64, rho: f64, c: f64) -> Self

Creates a Buckingham potential from rho parameterization.

V(r) = A * exp(-r / rho) - C / r^6

Arguments

• a: Repulsion amplitude
• rho: Softness parameter (rho = 1/b)
• c: Dispersion coefficient

pub fn a(&self) -> T

Returns the A parameter.

pub fn c(&self) -> T

Returns the C parameter.

Trait Implementations

impl<T: Clone> Clone for Buck<T>

fn clone(&self) -> Buck<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for Buck<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: PartialEq> PartialEq for Buck<T>

fn eq(&self, other: &Buck<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Vector> Potential2<T> for Buck<T>

fn energy(&self, r_sq: T) -> T

Computes the potential energy.

V(r) = A * exp(-B * r) - C / r^6

fn force_factor(&self, r_sq: T) -> T

Computes the force factor.

dV/dr = -A*B*exp(-B*r) + 6*C/r^7
S = -(dV/dr)/r = A*B*exp(-B*r)/r - 6*C/r^8

fn energy_force(&self, r_sq: T) -> (T, T)

Computes energy and force factor together (optimized).

Shares the computation of r, r_inv, r_sq_inv, r6_inv, and exp_term.

impl<T: Copy> Copy for Buck<T>

impl<T> StructuralPartialEq for Buck<T>