Fig. 5.7
Phonon dispersion curves for three polymorphs of FOX-7. The
gap between the phonon bath and doorway modes is
highlighted with a green box . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Fig. 5.8
Comparison of (left) g x
ð Þ and (right) X
2
ð Þ for the three
polymorphs of FOX-7. The phonon bath and doorway mode
regions in g x
ð Þ are indicated in yellow and purple,
respectively. Note that X
2
ð Þ have been normalized by
R
g x
ð Þ to
account for a different number of atoms (and hence vibrational
modes) in the unit cell according to the indirect up-pumping
mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Fig. 5.9
INS spectrum (10 K) for c-FOX-7. The (black) experimental
spectrum is given alongside the (blue) simulated spectra using
increasing densities of wave vectors for the phonon
calculations. Note that only first order quantum events are
simulated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Fig. 5.10 Overtone contributions to vibrational up-pumping in FOX-7
polymorphs. The overtones are shown for (blue) N ¼ 2 and
(green) N ¼ 3, and overlain by g x
ð Þ (black). Plots are shown
for a a-FOX-7, b b-FOX-7 and c c-FOX-7 . . . . . . . . . . . . . . . . 174
Fig. 6.1
Final predicted sensitivity order for the molecular energetic
materials. Note that in all cases, complete phonon dispersion
curves are used, except for TATP and d-HMX, for which
C-point density of states are used. a Impact sensitivity based
on the overtone up-pumping model (Model 3 in Table 6.1).
b Impact sensitivity based on the temperature-dependent twolayer model (T = 300 K). The difference in y-axis scale results
from the number of up-pumping pathways considered in each
case, and the addition of temperature in (b) . . . . . . . . . . . . . . . . 182
List of Figures
xxvii
Phonon dispersion curves for three polymorphs of FOX-7. The
gap between the phonon bath and doorway modes is
highlighted with a green box . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Fig. 5.8
Comparison of (left) g x
ð Þ and (right) X
2
ð Þ for the three
polymorphs of FOX-7. The phonon bath and doorway mode
regions in g x
ð Þ are indicated in yellow and purple,
respectively. Note that X
2
ð Þ have been normalized by
R
g x
ð Þ to
account for a different number of atoms (and hence vibrational
modes) in the unit cell according to the indirect up-pumping
mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Fig. 5.9
INS spectrum (10 K) for c-FOX-7. The (black) experimental
spectrum is given alongside the (blue) simulated spectra using
increasing densities of wave vectors for the phonon
calculations. Note that only first order quantum events are
simulated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Fig. 5.10 Overtone contributions to vibrational up-pumping in FOX-7
polymorphs. The overtones are shown for (blue) N ¼ 2 and
(green) N ¼ 3, and overlain by g x
ð Þ (black). Plots are shown
for a a-FOX-7, b b-FOX-7 and c c-FOX-7 . . . . . . . . . . . . . . . . 174
Fig. 6.1
Final predicted sensitivity order for the molecular energetic
materials. Note that in all cases, complete phonon dispersion
curves are used, except for TATP and d-HMX, for which
C-point density of states are used. a Impact sensitivity based
on the overtone up-pumping model (Model 3 in Table 6.1).
b Impact sensitivity based on the temperature-dependent twolayer model (T = 300 K). The difference in y-axis scale results
from the number of up-pumping pathways considered in each
case, and the addition of temperature in (b) . . . . . . . . . . . . . . . . 182
List of Figures
xxvii