Pure rotational spectroscopic measurements on the electronic ground states of Hafnium monosulfide and Thorium monosulfide in highly excited vibrational states

Pure rotational transitions for HfS and ThS have been measured in highly excited vibrational states. For HfS, rotational transitions have been recorded in up to the 19th excited vibrational state, whereas for ThS measurements extend up to the 17th excited vibrational state. Pure rotational transitions have also been recorded for Th³⁴S for the first time. In both cases isotopically invariant analyses have been performed and very accurate equilibrium bond lengths have been determined.