Are H–He–Cl and H–Ne–Cl metastable species? A computational study

Ab initio calculations at the B3LYP, MP2 and CISD levels of theory were performed on the noble-gas-containing compounds H–He–Cl and H–Ne–Cl. The calculations indicate that the H–He–Cl molecule should be metastable with an activation barrier of 68 kJ mol−1 at the CISD level for the lowest-energy fragmentation to HCl and He. However, similar calculations for H–Ne–Cl failed to locate a stable species except at the B3LYP level. This result suggests that it should be possible to generate and observe H–He–Cl at sufficiently low temperatures.