The half-metallic properties of novel CuHg2Ti-type Mn2ZnSi full-Heusler compound were examined by density functional theory (DFT) calculations. The electronic band structures and density of states of the Mn2ZnSi compound show that spin-up electrons are metallic, but the spin-down bands are semiconductor with a gap of 0.48 eV, and the spin-flip gap is of 0.28 eV. The Mn2ZnSi Heusler compound has a magnetic moment of 2 mu(B) at the equilibrium lattice constant a = 5.80 angstrom. The Mn2ZnSi full-Heusler compound is ferrimagnetic and maintains the half-metallic character having 100% polarization for lattice constants ranging between 5.62 and 6.91 angstrom. (C) 2012 Elsevier B.V. All rights reserved.