dft.forces

DFT force consistency checks.

import mlx_atomistic.dft.forces

Classes

`SCFForceConsistencyResult`

class SCFForceConsistencyResult
    def __init__(result: SCFResult, analytic_forces: mx.array, finite_difference_forces: mx.array, max_abs_error: float, rms_abs_error: float, displacement: float, samples: list[dict[str, float | int]])

SCF total-energy finite-difference force check.

Parameters

Name	Type	Default	Description
`result`	`SCFResult`
`analytic_forces`	`mx.array`
`finite_difference_forces`	`mx.array`
`max_abs_error`	`float`
`rms_abs_error`	`float`
`displacement`	`float`
`samples`	`list[dict[str, float \| int]]`

Methods

`to_dict`

def to_dict() -> dict

Return a JSON-safe summary.

Returns

dict

Functions

`scf_total_energy_forces`

def scf_total_energy_forces(system: DFTSystem, *, config: SCFConfig | None = None, xc_functional: ExchangeCorrelationFunctional | None = None, displacement: float = 0.001, reuse_scf_state: bool = True) -> SCFForceConsistencyResult

Compare SCF Hellmann-Feynman forces with total-energy finite differences.

The analytic force is the force reported by run_scf, which includes electronic local-pseudopotential forces and center-center repulsion for a DFTSystem. The finite-difference force is -[E(R + δ) - E(R - δ)] / 2δ after re-running SCF for each displacement.

Parameters

Name	Type	Default
`system`	`DFTSystem`
`config`	`SCFConfig \| None`	`None`
`xc_functional`	`ExchangeCorrelationFunctional \| None`	`None`
`displacement`	`float`	`0.001`
`reuse_scf_state`	`bool`	`True`

Returns

SCFForceConsistencyResult