Accurate bond dissociation energies (D0) for FHF^- isotopologues

Accurate bond dissociation energies (D 0) are determined for three isotopologues of the bifluoride ion (FHF^-). While the zero-point vibrational contributions are taken from our previous work (P. Sebald, A. Bargholz, R. Oswald, C. Stein, P. Botschwina, J. Phys. Chem. A, DOI: 10.1021/jp3123677), the equilibrium dissociation energy (D e ) of the reaction FHF^-→ F^-+ HF was obtained by a composite method including frozen-core (fc) CCSD(T) calculations with basis sets up to cardinal number n = 7 followed by extrapolation to the complete basis set limit. Smaller terms beyond fc-CCSD(T) cancel each other almost completely. The D 0 values of FHF^-, FDF^-, and FTF^- are predicted to be 15,176, 15,191, and 15,198 cm^-1, respectively, with an uncertainty of ca. 15 cm^-1.