Total atomization energies and heats of formation of small silicon clusters Sin and their ions are calculated using G4 (n = 2-13) and CCSD(T)/CBS (aug-cc-pV(n+d) Z for n = 2-6) methods. Experimental data for Si-n were available with large uncertainties. A new ground state structure for Si-11(-) was located. Using Delta H-f degrees (Si, 298 K) - 451.5 kJ/mol, Delta H-f degrees (Si-n, 298 K) are computed as: Si-2: 588/588 kJ/mol (G4/CBS), Si-3: 625/632, Si-4: 633/639, Si-5: 669/692, Si-6: 675/701, Si-7: 698, Si-8: 866, Si-9: 872, Si-10: 833, Si-11: 996, Si-12: 1051 and Si-13: 1158. Adiabatic electron affinities, ionization, binding and dissociation energies of Si-n are determined. (c) 2013 Elsevier B.V. All rights reserved.