Enthalpies of formation and bond dissociation energies at 298.15 K for molecules containing all four halogen atoms were calculated by CCSD(T) using double- and triple-ζ correlation-consistent basis sets, extrapolated to the complete basis set limit by the infinite basis (IB) method. The small molecules X2, HX, CH2X, CH3X (X = H, F, Cl, Br, I), ClF, BrF, BrCl, IF, ICl, CX (X = H, F, Cl, Br), and CHX (X = H, F, Cl) constituted the benchmark set. The cc-pV(n+d)Z (n = D,T) basis sets were used for chlorine, and two different sequences of conventional basis sets for iodine. The sequence consisting of the smaller SV4P and 6-311G(3df) basis sets for iodinedenoted by (cc)led to a slightly better performance. The IB extrapolation parameters were obtained by the minimization of the deviation between the zero-point exclusive atomization energies calculated by IB and those calculated by a combined Gaussian/exponential function using a sequence of three cc-pV(n+d)Z basis sets, with n = D, T, Q. All geometry optimizati...