Atomic Strain

Measure local deformation by comparing atomic neighborhoods against a reference configuration.

Parameters

Parameter	Type	Default	Description
`cutoff`	`float`	`3.0`	Cutoff radius for neighbor search.
`reference`	`file`	—	Reference LAMMPS dump file. If omitted, the current frame is used, which usually produces near-zero strain.
`eliminateCellDeformation`	`bool`	`false`	Eliminate cell deformation before the local fit.
`assumeUnwrapped`	`bool`	`false`	Assume coordinates are already unwrapped.
`calcDeformationGradient`	`bool`	`true`	Compute deformation gradient `F`.
`calcStrainTensors`	`bool`	`true`	Compute strain tensors.
`calcD2min`	`bool`	`true`	Compute `D2min`, the non-affine residual.

Output

`{outputBase}_atomic_strain.msgpack`

type StrainTensor = [float, float, float, float, float, float];
type DeformationGradient = [float, float, float, float, float, float, float, float, float];

interface PerAtomProperties {
    id: int;
    shear_strain: float;
    volumetric_strain: float;
    strain_tensor?: StrainTensor;
    deformation_gradient?: DeformationGradient;
    D2min: float | null;
    invalid: boolean;
}

interface AtomicStrainOutput {
    main_listing: {
        cutoff: float;
        num_invalid_particles: int;
        average_shear_strain: float;
        average_volumetric_strain: float;
        max_shear_strain: float;
    };
    "per-atom-properties": PerAtomProperties[];
}

Atomic Strain

Parameters

Output

`{outputBase}_atomic_strain.msgpack`

See Also

On this page