Abstract
Analytic expressions for tunneling frequencies through high periodic barriers are derived. The expression for wells of threefold symmetry is applied to the analysis of microwave data on CH3SiF3, CH3SiH3, and CH3SiD3 and values of the barrier heights of 1 kcal, 1.5 kcal, and 1.5 kcal per mole, respectively, are obtained, which are in reasonable agreement with previously obtained values.