RESUMEN
The dynamics of the title reaction are investigated using both the time-dependent quantum wave packet and the quasi-classical trajectory methods and employing a recently developed adiabatic ground 1(3)A'' potential energy surface [Gomez-Carrasco et al. J. Chem. Phys. 2004, 121, 4605]. By comparison to the quantum J = 0 reaction probabilities, the QCT method is first validated for the title reaction and further employed to produce the integral cross sections and rate constants. No resonance structures have been observed in both the QCT J = 0 and the quantum reaction probabilities of OH + F as well as in the QCT integral cross sections of both product channels, while there are some undulations in the calculated quantum reaction probabilities of HF + O. It is also found that Coriolis coupling effects play a significant role in the quantum calculation and that formation of the OH product is favored over the HF product in the reactive system.
RESUMEN
Quantitative structure-activity relationship models for the prediction of the mean and the maximum atmospheric degradation half-life values of persistent organic pollutants were developed based on the linear heuristic method (HM) and non-linear gene expression programming (GEP). Molecular descriptors, calculated from the structures alone, were used to represent the characteristics of the compounds. HM was used both to pre-select the whole descriptor sets and to build the linear model. GEP yielded satisfactory prediction results: the square of the correlation coefficient r(2) was 0.80 and 0.81 for the mean and maximum half-life values of the test set, and the root mean square errors were 0.448 and 0.426, respectively. The results of this work indicate that the GEP is a very promising tool for non-linear approximations.
