Abstract: Until now,there are very little public data about the molecular structures and molecular spectroscopy in plutonium hydride.The different geometrical structures and potential energy curves of the molecule PuH₃ are calculated with the discrete variational method (DVM),which is based upon the density functional theory.The optimal data of pyramidal molecule PuH₃ on the ground level are as follows:bond angle θ (H-Pu-H)=119.102°,bond length Pu-H=2.097726Å,the distance of H-H is 3.616817Å,total orbital energy is -19868.834 a.u.,Fermi energy level E_f=-16.856eV.The equivalent molecular state in inverse symmetry and the total orbital energy in mass centric coordinates are discussed.With full-electronic calculation,the results of PuH₂ and PuH₃ are compared.

Key words: PuH₃, geometrical structures, potential energy curve, ab initio, density functional theory