import type { WindowType } from '../fft';
import type { MdFrequencyUnit } from './frequency-units';
import type { Complex } from './types';
import type { Pbc } from '../structure';
import type { Matrix3x3 } from '../math';
import type { TrajectoryPositionStream, TrajectorySignal } from '../trajectory';
import type { VelocitySource } from '../vacf';
export type TrajectoryFrequencyUnit = MdFrequencyUnit | `1/step`;
export declare const TRAJECTORY_FREQUENCY_UNITS: readonly ["THz", "cm^-1", "1/step"];
type SpectralActivity = `active` | `inactive` | `unknown`;
export type SpectroscopyPreprocessing = `body_fixed` | `remove_com` | `raw`;
export declare const RAMAN_CHANNELS: readonly ["isotropic", "anisotropic", "vv", "vh", "unpolarized"];
export type RamanChannel = (typeof RAMAN_CHANNELS)[number];
export type InfraredSignal = {
    kind: `dipole`;
    series: TrajectorySignal;
} | {
    kind: `polarization`;
    series: TrajectorySignal;
    branch_continuous: true;
} | {
    kind: `current`;
    series: TrajectorySignal;
};
export type RamanSignal = {
    kind: `polarizability`;
    series: TrajectorySignal;
};
export interface TrajectorySpectroscopyInput {
    positions: TrajectoryPositionStream;
    masses: Float64Array;
    velocities?: TrajectorySignal | null;
    infrared_signal?: InfraredSignal | null;
    raman_signal?: RamanSignal | null;
    time_step?: number;
    time_unit?: string;
    metadata?: Record<string, unknown>;
}
export interface TrajectorySpectroscopyOptions {
    frequency_unit?: TrajectoryFrequencyUnit;
    preprocessing?: SpectroscopyPreprocessing;
    velocity_source?: VelocitySource | `auto`;
    window?: WindowType;
    zero_pad_factor?: number;
    raman_channel?: RamanChannel;
}
export interface TrajectorySpectrumCurve {
    frequencies: number[];
    power: number[];
    normalized_power: number[];
    frequency_unit: TrajectoryFrequencyUnit;
    sample_interval: number;
    frequency_spacing: number;
    rayleigh_resolution: number;
    nyquist: number;
}
type RamanSpectrumResult = Record<RamanChannel, TrajectorySpectrumCurve> & {
    selected_channel: RamanChannel;
};
interface TrajectorySpectralPeak {
    frequency: number;
    mode_label?: string;
    ir_activity: SpectralActivity;
    raman_activity: SpectralActivity;
    ir_score: number | null;
    raman_score: number | null;
    vdos_prominence: number;
    ir_prominence: number;
    raman_prominence: number;
    potentially_mixed: boolean;
    displacement?: Complex[][];
    displacement_unavailable_reason?: string;
}
export interface TrajectorySpectroscopyResult {
    vdos: TrajectorySpectrumCurve;
    ir: TrajectorySpectrumCurve | null;
    raman: RamanSpectrumResult | null;
    peaks: TrajectorySpectralPeak[];
    frequency_unit: TrajectoryFrequencyUnit;
    preprocessing: SpectroscopyPreprocessing;
    velocity_source: VelocitySource;
    reference_positions: number[][];
    elements: string[];
    masses: number[];
    pbc: Pbc;
    reference_lattice: Matrix3x3 | null;
    metadata: Record<string, unknown>;
}
export declare const arrays_equal: <Value>(left: ArrayLike<Value> | undefined, right: ArrayLike<Value>) => boolean;
export declare function validate_trajectory_signal(signal: TrajectorySignal, expected_shape?: number[], label?: string): void;
export declare function standard_masses_for_elements(elements: string[]): Float64Array;
export declare const calc_trajectory_spectroscopy: (input: TrajectorySpectroscopyInput, options?: TrajectorySpectroscopyOptions) => TrajectorySpectroscopyResult;
export {};