Abstract: With relativistic effective cores potential(RECP) for Cu and Te atom,B3LYP method with LANL2DZ basis set is used to optimize structure of CuTe,Cu₂ and Cu₂Te molecules.It shows that the ground state of CuTe and Cu₂ molecules is ²Π and ¹∑_g⁺ respectively and the ground state of Cu₂Te molecule is C_2V symmetry ¹A₁ state.Dissociation energy,harmonic frequency and force constant are calculated.Murrell-Sorbie potential energy functions of CuTe and Cu₂ molecules are fitted by least square fitting.Potential energy function of Cu₂Te ground state is given by many-body expansion theory.Potential surface shows clearly structure of Cu₂Te molecule at ground state.

Key words: Cu₂Te, density functional method, many-body expansion, potential energy function