VOLT
Plugins

Structure Identification

Crystal structure identification algorithms for atomistic simulations.

Overview

Structure Identification classifies atoms by their local structural environment to detect BCC, FCC, HCP, diamond cubic, and other crystal structures. It helps identify phase boundaries, defects, and amorphous regions in simulation data.

Parameters

ParameterTypeDefaultDescription
modestringCNAIdentification algorithm to use. Options: CNA, PTM, DIAMOND.
rmsdfloat0.1RMSD threshold for PTM classification (only applies when using PTM).

Output

{outputBase}_structure_identification.msgpack

type Vec3 = [float, float, float];

// [x, y, z, w]
type Quaternion = [float, float, float, float];

// CNA / DIAMOND mode
interface PerAtomProperties {
    id: int;
    structure_type: int;
    structure_name: string;
    pos: Vec3;
}

// PTM mode
interface PTMPerAtomProperties {
    id: int;
    structure_type: int;
    pos: Vec3;
    correspondence: int;
    orientation: Quaternion;
}

interface StructureIdentificationOutput {
    main_listing: {
        total_atoms: int;
        analysis_method: string;
        // For each detected structure type, a pair of keys is added dynamically:
        //   `{type}_count`: int
        //   `{type}_percentage`: float
        [key: `${string}_count`]: int;
        [key: `${string}_percentage`]: float;
        total_identified: int;
        total_unidentified: int;
        identification_rate: float;
        unique_structure_types: int;
    };
    "per-atom-properties": PerAtomProperties[] | PTMPerAtomProperties[];
}

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