Enum CheqError 

pub enum CheqError {
    ParameterNotFound(u8),
    NotConverged {
        max_iterations: u32,
        delta: f64,
    },
    LinalgError(String),
    IoError {
        path: PathBuf,
        source: Error,
    },
    DeserializationError(Error),
    NoAtoms,
}

The primary error type for all fallible operations in the cheq library.

This enum is designed to be comprehensive, providing clear and actionable information for each potential failure mode, from I/O issues to numerical convergence problems. It implements std::error::Error, allowing it to be composed with other error types in application code.

Variants

ParameterNotFound(u8)

Indicates that the parameters for a specific element, identified by its atomic number, could not be found in the provided Parameters set.

This is a common error when attempting to calculate charges for a molecule containing an element not defined in the parameter file.

NotConverged

Occurs when the Self-Consistent Field (SCF) iterative process fails to converge to the desired tolerance within the maximum number of allowed iterations.

This can happen with unusual molecular geometries or problematic parameter sets. The final charge difference (delta) is provided for diagnostic purposes.

Fields

max_iterations: u32

The maximum number of iterations that were performed.

delta: f64

The largest absolute change in any atomic charge during the final iteration.

LinalgError(String)

A failure within the underlying linear algebra solver, for example, if the matrix system is singular or ill-conditioned.

IoError

An I/O error that occurred while attempting to read a parameter file.

The path to the file and the underlying I/O error are provided for context.

Fields

path: PathBuf

The path of the file that caused the I/O error.

source: Error

The underlying std::io::Error.

DeserializationError(Error)

An error that occurred while parsing a parameter file, typically indicating invalid TOML or a structural mismatch with the expected Parameters format.

NoAtoms

A validation error indicating that the input slice of atoms was empty. At least one atom is required to perform a calculation.

Trait Implementations

impl Debug for CheqError

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

Formats the value using the given formatter.

impl Display for CheqError

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

Formats the value using the given formatter.

impl Error for CheqError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for CheqError

fn from(source: Error) -> Self

Converts to this type from the input type.