Table 1.
The calculated activation barriers E (kcal/mol), zero-point-energy corrected barriers EZPE (kcal/mol), and pre-exponential factors, log (A, s−1) of thermal decomposition of PETN, HMX, DADNE, TATB, and BNFF.
| Reaction | Isolated Molecule | (mnl) Crystal Surface | ||||||
|---|---|---|---|---|---|---|---|---|
| E | EZPE | log A | E | EZPE | log A | |||
| PETN (C5H8N4O12) | (101) | |||||||
| I | NO2• loss | 41.8 (41.8) a | 36.6 [34.9] b | 17.5 | 40.0 (40.0) | 35.3 | 17.8 | |
| II | HONO | 33.6 (−18.6) | 28.8 [40.5] | 13.4 | 34.6 (−10.4) | 29.5 [40.9] | 14.2 | |
| β-HMX (C4H8N8O8) | (100) | |||||||
| I | NO2• loss | 44.8 (44.8) | 40.2 [40.9] | 18.3 | 40.1 (40.1) | 37.4 | 17.3 | |
| II | HONO | 40.4 (−2.4) | 35.8 [47.1] | 13.4 | 41.0 (−3.2) | 38.1 [47.7] | 14.8 | |
| δ-HMX (C4H8N8O8) | Polar (001) | |||||||
| I | NO2• loss | charge state [0] b | 45.1 (45.1) | 40.3 [41.5] | 18.4 | - | ||
| [+] c | 12.7 (−24.3) | - [10.1] | 13.4 | ~20.7 (−6.0) | ||||
| [−] c | 17.0 (17.0) | - [15.4] | - | ~20.1 (20.1) | ||||
| II | HONO | [0] b | 38.0 (0.7) | 33.3 [44.1] | 13.3 | - | ||
| [+] c | 12.7 (−13.6) | - [10.1] | 13.4 | ~20.7 (12.9) | ||||
| DADNE (C2H4N4O4) | (010) | |||||||
| I | NO2• loss | 69.1 (69.1) | 65.4 [68.6] | 19.0 | 66.4 (66.4) | 62.3 | 19.0 | |
| II | CONO | 54.3 (−1.0) | 52.1 [61.5] | 13.5 | 55.3 (0.1) | 52.6 [64.6] | 13.8 | |
| III | 1 | CH2N2 loss (step1) | 49.0 (14.7) | 45.5 [49.4] | 14.3 | 57.3 (35.2) | 53.3 [62.2] | 14.0 |
| 2 | CH2N2 loss (step2) | 34.0 (14.4) | 32.1 [34.4] | 14.9 | 56.5 (38.8) | 53.4 [60.7] | 15.4 | |
| 3 | CH2N2 loss (step3) | 44.9 (34.6) | 41.0 [47.9] | 13.7 | 52.9 (44.5) | 48.6 [58.8] | 15.2 | |
| 4 | NO2• loss from AIDNE | 50.7 (50.7) | 46.2 [47.8] | 19.1 | 67.1 (67.1) | 61.9 | 19.3 | |
| TATB (C6H6N6O6) | (001) | |||||||
| I | NO2• loss | 74.9 (74.9) | 70.7 [65.8] | 18 | 75.0 (75.0) | 71.1 | 19 | |
| II | CONO | 54.9 (4.3) | 52.5 [58.6] | 13.1 | 54.0 (5.6) | 51.5 [58.0] | 13.8 | |
| III | 1 | H2O loss (step1) | 44.5 (37.5) | 43.2 [42.1] | 13.0 | 49.0 (43.0) | 47.3 [46.1] | 13.8 |
| 2 | H2O loss (step2) | 65.3 (40.9) | 62.6 [68.6] | 13.4 | 74.6 (44.5) | 71.3 [74.3] | 14.7 | |
| 3 | H2O loss (step3) | 52.8 (41.7) | 47.5 [58.8] | 13.3 | 59.1 (49.5) | 53.2 [65.5] | 14.3 | |
| 4 | HONO loss | 95.4 (42.5) | 91.3 [94.1] | 13.4 | - | - | - | |
| BNFF (C6N8O8) | (001) | |||||||
| I | NO2• loss | 63.2 (63.2) | 59.3 [56.2] | 17.9 | 60.1 (60.1) | 56.2 | 18.4 | |
| II | CONO | 49.5 (−9.5) | 47.2 [54.3] | 13.4 | 49.1 (−11.0) | 46.8 [51.4] | 13.3 | |
| III | RC CN2O3 | 48.7 (36.4) | 45.7 [50.5] | 15.2 | 48.0 (31.7) | 45.1 [49.4] | 15.5 | |
| IV | RC CN2O2 | 47.1 (36.6) | 44.0 [48.9] | 16.3 | 44.2 (31.2) | 41.4 [45.8] | 15.4 | |
a The corresponding reaction energies are shown in parentheses; b Activation barriers and reaction energies obtained with hybrid PBE0 (for PETN, HMX, and DADNE) and B3LYP (for BNFF) functionals are shown in square brackets; c Activation barriers and reaction energies for decomposition reactions of ion radicals were obtained using M06 functional.