Adsorption energies of H and H2: a quantum-chemical study Milan Sil, Prasanta Gorai, Ankan Das, Dipen Sahu and Sandip K. Chakrabarti Eur. Phys. J. D, 71 2 (2017) 45 Published online: 28 February 2017 DOI: 10.1140/epjd/e2017-70610-4