The Study Of Molecular Structures Properties, Thermodynamic Properties For Zr-H (D, T) System And Excited States Of Ti-H System

Zirconium is the major metal of nuclear reaction. Zirconium and Zirconiumhydrides and isotopes have important theoretical study value and technologicalapplication. In the first part of the paper, using Density functional theory (DFT)Becke 3P86 method with Gaussian03W program, 8s7p3d external basis set is used bygen command for Zr. 6-311G^* with full-electron basis set is used for hydrogenisotopes. Microcosmic structure of ZrH₂,ZrD₂ and ZrT₂ and thermodynamicfunctions have been calculated in different temperature without external electric fieldand with external electric field. Finally, the relations of the temperatures, externalelectric field and hydrogen isotopes equilibrium pressure can be obtained.In different temperature,â–³H^Θ,â–³S^Θ,â–³G^Θof the reaction of Zirconium andhydrogen isotopes and equilibrium pressure of hydrogen isotopes are calculated,which educe the relations of equilibrium pressure and temperatures. In externalelectric field, the values of thermodynamic functions of polarity molecules have noany changes, but for non-polarity molecules ZrH₂, ZrD₂ and ZrT₂, microcosmicstructure and the values of thermodynamic functions have changes. Thenâ–³H^Θ,â–³S^Θ,â–³G^Θof the reaction of Zirconium and hydrogen isotopes and equilibrium pressure ofhydrogen isotopes are calculated. The relations of equilibrium pressure andtemperatures are educed, equilibrium pressure is compared in different temperatureand external electric field. It is obtained that the external electric field andtemperature have important effect in adsorption aspect of hydrogen isotopes.At thesame temperature, equilibrium pressure of hydrogen is reduced 10^-6 from F=-0.004a.u.to 0.004a.u. Therefore, it is considered that the external electric field and temperature are used to change the ability of adsorption of hydrogen isotopes, which is provedthat the Zirconium hydride is the better neutron moderator.14Mev neutron generator of the D-T fusion reaction is regarded as an importantneutron source. T-Ti target is the key technologies of the neutron generator. It hasimportant meaning to study the excited state. In the second part of the paper, using thesymmetry-adapted cluster-configuration interaction (SAC/SAC-CI), the ground,excited states of TiH₂ molecule are calculated by LANL2DZ basis set, which isconsidered the relativistic effective core potential. Microcosmic structure of ground,excited states are optimized. Excitation energy and oscillation strength are calculated.It offered the theory base for polyatomic molecules.