Variational Transition-State Theory with Optimized Orientation of the Dividing Surface and Semiclassical Tunneling Calculations for Deuterium and Muonium Kinetic Isotope Effects in the Free Radical Association Reaction H + C2H4 → C2H5 - Villà, Jordi; Corchado, José C; González-Lafont, Angels; Lluch, José M; Truhlar, Donald G (The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 1999)