Potential profiles showing the comparison of several ab initio methods. Panel (a) shows the calculated energy along the minimum energy path as a function of torsional angle for four ab initio methods. Panel (b) is a 2D contour plot comparing the calculated energies for CCSD(T)/cc-pVQZ and MP4(SDQ)/6-31++G(d,p); the plot is obtained by varying the torsional and HON bend angles while keeping the other coordinates fixed at their transition state values.
Ratio of number of ab initio data points picked up during growing to total number of data points as a function of number of trajectories. The results shown are for error tolerances of 2.0 kcal/mol and 0.25 kcal/mol, respectively.
Mean error estimator and mean true error versus total number of ab initio points used to construct the surfaces of several error tolerances. The straight lines are the least-squares fit to the power law.
Convergence of the classical rate coefficient with respect to error tolerance for cis → trans isomerization with 8 quanta of excitation energy assigned to the HON bending mode. The number of ab initio points used for each surface is also listed.
Computed tunneling rate or isomerized fraction versus error tolerance for a set of initial states of similar energies.
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