assyst.relaxations¶

Relaxation step of ASSYST.

class assyst.relaxations.CellRelax(max_steps: int = 100, force_tolerance: float = 0.001, algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS')[source]¶

Bases: Relax

Minimize energy while keeping relative positions and volume constant.

apply_filter_and_constraints(structure: Atoms)[source]¶: Hook to allow subclasses to add filters and constraints.

class assyst.relaxations.FullRelax(max_steps: int = 100, force_tolerance: float = 0.001, algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS', pressure: float = 0.0)[source]¶

Bases: Relax

Minimize energy with respect to internal positions and cell without constraints.

apply_filter_and_constraints(structure: Atoms)[source]¶: Hook to allow subclasses to add filters and constraints.

pressure: float = 0.0¶

class assyst.relaxations.Relax(max_steps: int = 100, force_tolerance: float = 0.001, algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS')[source]¶

Bases: object

Minimize energy with respect to internal positions.

Also used as a base class for all other relaxation classes.

algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS'¶

apply_filter_and_constraints(structure: Atoms)[source]¶: Hook to allow subclasses to add filters and constraints.

force_tolerance: float = 0.001¶

max_steps: int = 100¶

relax(structure: Atoms) → Atoms[source]¶

Relax a structure and return result.

Structure must have a calculator attached. Returned structure will have a SinglePointCalculator with the final energy, forces and stresses attached.

Parameters:: structure (ase.Atoms) – structure to relax
Returns:: relaxed structure with attached single point calculator.
Return type:: ase.Atoms

class assyst.relaxations.SymmetryRelax(max_steps: int = 100, force_tolerance: float = 0.001, algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS', pressure: float = 0.0)[source]¶

Bases: Relax

Minimize energy with respect to internal positions and cell, while keeping space group fixed.

apply_filter_and_constraints(structure: Atoms)[source]¶: Hook to allow subclasses to add filters and constraints.

pressure: float = 0.0¶

class assyst.relaxations.VolumeRelax(max_steps: int = 100, force_tolerance: float = 0.001, algorithm: Literal['LBFGS', 'BFGS', 'FIRE'] = 'LBFGS', pressure: float = 0.0)[source]¶

Bases: Relax

Minimize energy while keeping relative positions and cell shape constant.

apply_filter_and_constraints(structure: Atoms)[source]¶: Hook to allow subclasses to add filters and constraints.

pressure: float = 0.0¶

assyst.relaxations.relax(structures: Iterable[Atoms], settings: Relax, calculator: AseCalculatorConfig | Calculator) → Iterator[Atoms][source]¶

Relax structures according the given relaxation settings.

Output structures have the final energy and force attached as ase’s SinglePointCalculator.

Parameters:

structures (collections.abc.Iterable of ase.Atoms) – the structures to minimize
settings (Relax) – the kind of relaxation to perform (position, volume, etc.)
calculator (AseCalculatorConfig or ase.calculators.calculator.Calculator) – the energy/force engine to use

Yields:

ase.Atoms – the corresponding relaxed configuration to each input structure