4.4 Basic Features of Atom–Diatom Reactions
143
Fig. 4.17 The j = 0, v = 0 probability of the Li + FH reaction plotted as a function of total energy
for increasing value of the total angular momentum
This is, indeed, the case shown in Fig. 4.18 for the thermal rate coefficient of N
+ N 2 computed using different methods and compared with values given in related
experimental work. As can be clearly seen from the figure, the largest deviation
from high level quantum calculations are for quasiclassical (QCT) results. A clear
improvement is obtained when using the Reactive IOSA reduced dimensionality
quantum and the semiclassical SC-IVR techniques. The lowest three curves are
generated using the mentioned high level quantum techniques on slightly different
PESs and confirm that quantum accurate values are on the average smaller. Such
validation has allowed us to use the developed procedure with some confidence
to assemble a database of vibrational state-to-state rate coefficients to be used by
the European Space Agency for modeling the higher temperature environment of
reentering spacecrafts.
143
Fig. 4.17 The j = 0, v = 0 probability of the Li + FH reaction plotted as a function of total energy
for increasing value of the total angular momentum
This is, indeed, the case shown in Fig. 4.18 for the thermal rate coefficient of N
+ N 2 computed using different methods and compared with values given in related
experimental work. As can be clearly seen from the figure, the largest deviation
from high level quantum calculations are for quasiclassical (QCT) results. A clear
improvement is obtained when using the Reactive IOSA reduced dimensionality
quantum and the semiclassical SC-IVR techniques. The lowest three curves are
generated using the mentioned high level quantum techniques on slightly different
PESs and confirm that quantum accurate values are on the average smaller. Such
validation has allowed us to use the developed procedure with some confidence
to assemble a database of vibrational state-to-state rate coefficients to be used by
the European Space Agency for modeling the higher temperature environment of
reentering spacecrafts.