Randomization and isomerization rate constants for isocyanogen

Distribution of vibrational potential energy in molecular systems

“…1,4 The potential energy distribution at an energy about 2 eV above threshold is shown in Fig. 2 for each reactant.…”

“…For small molecules like NCNC, 4 and a little bit larger, 13 it is possible to achieve polynomial fits to very highlevel ab initio energies. Restricting ourselves to isomerization reactions and to energies sufficiently ''high'' for the system to be at the correspondence limit, we can assume that the topology of such a potential energy surface will include the couplings between all of the motions in a proper manner.…”

Trajectory Dynamics Study of the Ar + CH4 Dissociation Reaction at High Temperatures: the Importance of Zero-Point-Energy Effects

“…Conversely, as a result of the high endoergicity of reaction 1, the problem of zero-point energy (ZPE) conservation in the CH 3 product should be the most relevant disadvantage of using classical trajectories, even in the combustion range of temperatures. However, many strategies have been proposed [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] to approximately correct for this problem. Among these, some are designated as active, because they seek to correct the ZPE leakage along the integration of each trajectory, while the others take into account only the energies of reactant and product molecules (and sometimes that of the transition-state structure) and, hence, are called passive methods.…”

Defective modelling of chaotic motions on empirical potential energy surfaces

“…The potential energy surfaces used were: for CH 3 NC = CH 3 CN, the empirical surface constructed by Sumpter and Thompson; 7 and for NCNC = NCCN, an 870-point ''clampednuclei'' MP2/6-31G* ab initio potential surface. 6,8 Fig . 1 shows the key properties of the two potential energy surfaces.…”