Theoretical study of decomposition pathways for HArF and HKrF

To provide theoretical insights into the stability and dynamics of the new rare gas compounds HArF and HKrF, reaction paths for decomposition processes HRgF → Rg → HF and HRgF → H + Rg + F (Rg=Ar, Kr) are calculated using ab initio electronic structure methods. The bending channels, HRgF → Rg + HF, are described by single-configurational MP2 and CCSD(T) electronic structure methods, while the linear decomposition paths, HRgF → H + Rg + F, require the use of multi-configurational wave functions that include dynamic correlation and are size extensive. HArF and HKrF molecules are found to be energetically stable with respect to atomic dissociation products (H+Rg+F) and separated by substantial energy barriers from Rg+HF products, which ensure their kinetic stability. The results are compatible with experimental data on these systems.