A sub-monolayer of atomic sodium was deposited on LiF(001) at 40-90 K. The adsorbed sodium atoms and clusters were dosed with HBr, to form HBr...Na-n/LiF(001) (n=1,2,...) complexes which were then irradiated by 610 nm laser-light to induce charge-transfer reactions. The reaction-product atomic H(g) was observed leaving the surface, by two-color Rydberg-atom TOF spectroscopy. The H-atom translational energy in its "fast" (0.9 eV) component exhibited structure (40+/-10 meV spacing) attributed to vibration of the NaBr residue at the surface following photoinduced reaction in Na...HBr. The cross-section of the harpooning event was obtained as 7.5x10(-19) cm(2) for the "fast" H-atom reaction-product. Investigation of the coverage and temperature dependencies of the H-atom signal and of temperature programmed desorption (TPD) and x-ray photoelectron spectra gave an activation barrier for surface diffusion of Na-atoms E-diff<170 meV. High-level ab initio calculations were employed to interpret the TOF and TPD spectra. The reaction precursors and products, Na-HBr, Na+-HBr, Na-2-HBr, Na2Br, NaBr, and NaBr-HBr, were investigated in terms of potential energy surfaces, equilibrium structures, binding energies, and vibrational frequencies. (C) 2003 American Institute of Physics.