Abstract
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 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.
Notes
a Equilibrium bond lengths chosen are 0.9168 Å for HF [Citation26] and 1.13961 Å for FHF− [Citation10].
a Using auxiliary basis sets AVnZ/JKFIT, AVnZ/MP2FIT, and AVnZ/OPTRI [Citation29–Citation32] in conjunction with geminal parameters 1.2, 1.4, and 1.5 for n = T, Q, and 5, respectively. The underlying Hartree–Fock calculations include CABS singles in all cases.
a Using ACVnZ basis sets.
a CP corrected values in parentheses. Valence electrons are correlated.
a Taken from Ref. [Citation10]; the corrected PEF is employed.
b Values from Ref. [Citation43] in parentheses.
c Values in parentheses from calculations with CCSD(T*)-F12b/AV5Z PEFs.