Callback allowing to sort chemical elements (atoms) in Hill order
$ npm install atom-sorter
const atomSorter = require('atom-sorter');
let atoms = ['H', 'Cl', 'C', 'O', 'N', 'Br'];
atoms.sort((a, b) => atomSorter(a, b));
// ['C', 'H', 'Br', 'Cl', 'N', 'O']