def _remove_atom_numbers_from_distance(feat_str):
    """
    Remove atom numbers from a distance feature string.
    
    Parameters
    ----------
    feat_str : str
        The string describing a single feature.
    
    Returns
    -------
    new_feat : str
        The feature string without atom numbers.
    
    """
    # Split the feature string in its parts
    parts = feat_str.split(' ')
    # Glue the desired parts back together
    new_feat = parts[0]
    for nr in [1,2,3,5,6,7,8]:
        new_feat += ' '+parts[nr]
    return new_feat