Validation of variational transition state theory with multidimensional tunneling contributions against accurate quantum mechanical dynamics for H+CH[sub 4]→H[sub 2]+CH[sub 3] in an extended temperature interval

Pu, Jingzhi; Truhlar, Donald G.
July 2002
Journal of Chemical Physics;7/22/2002, Vol. 117 Issue 4, p1479
Academic Journal
Variational transition state theory with multidimensional tunneling contributions (VTST/MT) is tested against quantum mechanical rate constants for the reaction H+CH[sub 4]→H[sub 2]+CH[sub 3] at temperatures up to 1000 K. The VTST/MT method can be and has been applied to many reactions that cannot be treated by rigorous quantum dynamics methods. Studying the accuracy of VTST/MT by comparison with accurate quantal results that are becoming available for systems of increasing size is important for validating the theory. In the present study, covering a factor of five in temperature, the VTST/MT method is found to have a mean deviation from accurate quantal rate constants for a six-body reaction of only 13% and maximum deviation of only 23%.


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