The Geometry and Property of H₃⁺ and H₄⁺ Molecular Ions

Ab initio calculations based on the levels HF and QCISD with basis set 6 311G^** have been applied to the molecular ion H₃⁺ and H₄⁺.It is shown that the equilateral triangle（D_3h ）is the unique geometry for ground state of H₃⁺,and there are 10 of possible stable geometrical configurations for H₄⁺.At the same time,it is shown that H₄⁺（D_4h ）and H（T_d）geometric forms are unstable.We have discussed in detail the Jahn Teller effect for both these configurations.