import type { AnyStructure } from '../structure';
import type { BondingStrategy } from '../structure/bonding';
import type { Pbc } from '../structure/pbc';
export declare const MAX_BOND_ANGLE = 180;
export declare const BOND_ANGLE_DEFAULT_BIN_WIDTH = 2;
export declare const TOTAL_TRIPLET_LABEL = "All angles";
export interface BondAngleOptions {
    strategy?: BondingStrategy;
    bin_width?: number;
    n_bins?: number;
    split_by_triplet?: boolean;
    center_elements?: readonly string[];
    neighbor_elements?: readonly string[];
    pbc?: Pbc;
}
export interface BondAngleTriplet {
    center_idx: number;
    neighbor_idxs: [number, number];
    triplet: string;
    angle: number;
}
interface BondAngleSeries {
    triplet: string;
    counts: number[];
    n_angles: number;
}
export interface BondAngleData {
    bin_centers: number[];
    bin_width: number;
    n_bins: number;
    n_angles: number;
    total: BondAngleSeries;
    by_triplet: BondAngleSeries[];
}
export declare function resolve_angle_bins({ bin_width, n_bins, }: Pick<BondAngleOptions, `bin_width` | `n_bins`>): {
    n_bins: number;
    bin_width: number;
};
export declare const angle_bin_centers: (n_bins: number, bin_width: number) => number[];
export declare const angle_bin_index: (angle: number, n_bins: number, bin_width: number) => number;
export declare function calc_bond_angles(structure: AnyStructure, options?: BondAngleOptions): BondAngleTriplet[];
export declare function bin_bond_angles(triplets: readonly BondAngleTriplet[], options?: Pick<BondAngleOptions, `bin_width` | `n_bins` | `split_by_triplet`>): BondAngleData;
export declare const calc_bond_angle_distribution: (structure: AnyStructure, options?: BondAngleOptions) => BondAngleData;
export {};