ZnZrAl2　is　a　kind　of　heterogeneous　nucleation　to　promote　the　refine　of　grain　of　ZA43　alloy.　ZnZrAl2　intermetallic　is　also　considered　as　a　candidate　for　superalloys.　The　crystal　lattice　structure,　alloy　thermodynamics　and　mechanical　properties　of　ZnZrAl2　intermetallic　compound　were　investigated　by　ab　initio　calculations　based　on　density　functional　theory　(DFT).　In　particular,　the　site　preference　of　atoms　in　different　sublattices　was　predicted　based　on　alloy　thermodynamics.　At　ground　state,　the　most　stable　structure　is　L12　structure　with　sublattice　model　(Zn)1a(Zr0.3333Al0.6667)3c　or　(Zr)1a(Zn0.3333Al0.6667)3c,　and　the　occupying　preferences　of　Zn,　Zr　and　Al　atoms　are　independent　with　the　increasing　temperature.　The　bulk,　shear,　Young＇s　modulus　and　the　Poisson＇s　ratio　of　the　L12　structure　ZnZrAl2　were　calculated　based　on　the　site　occupying　configurations.　The　results　show　that　ZnZrAl2　is　a　brittle　material　in　nature.　Electronic　structures　analysis　revealed　that　Al-Zr　atoms　possess　a　covalent　bonding　character,　while　the　Zn-Zr　atoms　have　a　metallic　bonding　character.　ZnZrAl2　has　stable　mechanical　properties　at　high　temperature.　The　grain　refinement　effect　of　ZnZrAl2　precipitates　in　Zn-Al　alloys　were　discussed　based　on　crystal　lattice　match　theory.　©　2016　Elsevier　Ltd