Struct SolverOptions 

pub struct SolverOptions {
    pub tolerance: f64,
    pub max_iterations: u32,
    pub lambda_scale: f64,
    pub hydrogen_scf: bool,
    pub basis_type: BasisType,
    pub damping: DampingStrategy,
}

Configuration parameters for the charge equilibration solver.

This struct encapsulates the numerical settings that control the iterative solution process in the QEq algorithm. Users can adjust these parameters to balance convergence speed with accuracy for different molecular systems and computational requirements.

Fields

tolerance: f64

The convergence tolerance for charge equilibration.

The solver iterates until the root-mean-square change in atomic charges between successive iterations falls below this threshold. Smaller values yield more accurate results but require more iterations.

max_iterations: u32

The maximum number of iterations allowed.

If convergence is not achieved within this limit, the solver will terminate and return the current best estimate. This prevents infinite loops in difficult cases.

lambda_scale: f64

The screening parameter scale factor.

This multiplier adjusts the orbital screening strength in Coulomb integral calculations. It corresponds to the λ parameter in the Rappe & Goddard paper. The original paper suggests a value of ~0.4913, often rounded to 0.5.

hydrogen_scf: bool

Whether to update hydrogen hardness each iteration (nonlinear SCF term).

When disabled, hydrogen uses a fixed hardness (lossy simplification). Enabled by default.

basis_type: BasisType

The type of basis functions to use for Coulomb integrals.

Defaults to BasisType::Sto (Slater-Type Orbitals) for maximum accuracy.

damping: DampingStrategy

The damping strategy for the SCF iteration.

Controls how charge updates are mixed between iterations to ensure convergence.

Trait Implementations

impl Clone for SolverOptions

fn clone(&self) -> SolverOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SolverOptions

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

Formats the value using the given formatter.

impl Default for SolverOptions

fn default() -> SolverOptions

Returns the “default value” for a type.

impl PartialEq for SolverOptions

fn eq(&self, other: &SolverOptions) -> 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 Copy for SolverOptions

impl StructuralPartialEq for SolverOptions