Geometrical and electronic structure of hydrated CH 5 + and CH 5 −

Different conformations of isolated and solvated CH ₅ ⁺ and CH ₅ ^? ions have been studied by CNDO method with Wiberg's parametrization. The anion has been found to have a most stable conformation ofD _3h symmetry both in the gas phase and in solution. AC _s symmetry conformation is the most stable one for the isolated cation, whereas a conformation withC _4v symmetry is energetically preferred in solution.