The Study Of Stereochemical Structure Of The Molecular Ion HD₂⁺

Due to the special applied value of the molecular ions (micro-cluster) in the field of material modification and absorption to light, the studies to the structure of molecular ions have been concerned since last decades. HD₂⁺ acts an important role in the micro-cluster family, and the explorations on HD₂⁺ have been worked deeply recently. These studies mainly concentrate on the experiments."Coulomb explosion"as a result of fast molecular ions penetrating any material is a very important and useful technique for the research on the stereochemistry structure of molecular ions. J. W. Miao used the technique to measure the internuclear separation and the binding energy of HD₂⁺ ,and the results indicate that the stereochemistry structure of HD₂⁺ is acute angle isosceles triangle. In 2004, D.Strasser et all found that the three particles of HD₂⁺ tend to dissociate with a geometry close to linear in the study of the breakup dynamics of HD₂⁺ and DH2+ following dissociative recombination with low energetic electrons. The conclusion illuminate that the acute angle isoceles triangle structure of HD₂⁺ is more steady and not easy to be dispersed. This paper is about the attempt to the theoretical works on the stereochemical structure study of HD₂⁺ ,by means of the basic idea of Arrangement-Channel Quantum Mechanics(ACQM). Our main conclusions are as follows: (1)Firstly, we get the ground state energy value is - 34.6196eV,with R_HD′ = R_HD= 2 a. u, R_DD′ = 1.9 a. u; (2)Secondly, we attain the dissociation energy for the two D+ is equality, but is different from the energy of H⁺ by adopting the dissymmetrical channel division. (3)Thirdly, comparing the energy needed for dissociating H+ form HD₂⁺ and H₃⁺ , we prove that the isosceles side of HD₂⁺ should be longer than the equal side of H3+ . (4)In the calculation of HD in the group molecular of HD₂⁺ , we mainly use the Thomas-Fermi potential to describe the screen effect and the results satisfy the values in experiment, which is helpful to improve the calculation of HD₂⁺ . We compare the values of HD₂⁺ gained from the basic idea of Arrangement-Channel Quantum Mechanics for many-body to the measured values in the experiments. There are some differences among these values , but all the conclusions illuminate that: the stereochemistry structure of HD₂⁺ is acute angle isosceles triangle, neither linear geometrical structure nor obtuse angle isosceles triangle, when it is steady. We also analyse the causation of the difference between our results and the measured values in the experiment.