def _get_atom_coord(component, at_id, conformer_type):
    """Retrieve 3D coordinates for the particular atom in a given
    conformer.

    Args:
        component (Component): component to be processed.
        at_id (int): atom id to be retrieved.
        conformer_type (ConformerType): conformer type

    Returns:
        rdkit.Geometry.rdGeometry.Point3D: 3D coordinates of the atom.
    """
    conf_id = component.conformers_mapping[conformer_type]

    return component.mol.GetConformer(conf_id).GetAtomPosition(at_id)