An energetics database of binary magnesium compounds has been developed from first-principles calculations. The systems investigated include Mg-X (X = As, Ba, Ca, Cd, Cu, Dy, Ga, Ge, La, Lu, Ni, Pb, Sb, Si, Sn and Y). The calculated lattice parameters and enthalpies of formation of binary compounds in these systems are compared with both experimental data and thermodynamic databases. (C) 2009 Elsevier Ltd. All rights reserved.