<reponame>Tarskin/MassyTools<gh_stars>1-10
carbon = [('13C', 0.0107, 1.00335)]
hydrogen = [('2H', 0.00012, 1.00628)]
nitrogen = [('15N', 0.00364, 0.99703)]
oxygen18 = [('18O', 0.00205, 2.00425)]
oxygen17 = [('17O', 0.00038, 1.00422)]
sulfur33 = [('33S', 0.0076, 0.99939)]
sulfur34 = [('34S', 0.0429, 1.9958)]
sulfur36 = [('36S', 0.0002, 3.99501)]

carbon = [('13C', 0.0107, 1.00335)]
hydrogen = [('2H', 0.00012, 1.00628)]
nitrogen = [('15N', 0.00364, 0.99703)]
oxygen18 = [('18O', 0.00205, 2.00425)]
oxygen17 = [('17O', 0.00038, 1.00422)]
sulfur33 = [('33S', 0.0076, 0.99939)]
sulfur34 = [('34S', 0.0429, 1.9958)]
sulfur36 = [('36S', 0.0002, 3.99501)]