Improved prediction of heats of formation of energetic materials using quantum mechanical calculations
Improved prediction of heats of formation of energetic materials using quantum mechanical calculations
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DOI：
10.1021/jp0536192
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发表时间：
2006-01-26
影响因子：
2.9
通讯作者：
Rice, BM
中科院分区：
文献类型：
--
作者：
Byrd, EFC;Rice, BM
我们提出了简单的原子和基团等效的方法，将分子的量子机械能转化为气相生成热的CHNO系统。此外，我们预测升华和蒸发热来自从量子力学计算的每个孤立分子的静电势获得的信息。升华热和汽化热与上述气相生成热结合，产生完全预测的凝相生成热。这些半经验的计算方法，校准使用实验信息，被施加到一系列的CHNO分子，没有实验信息被用于开发的方法。这些方法改进了Rice等人的早期努力[Rice，B. M.;派，S.五、Hare，J. Combust. Flame 1999，118，445]通过使用更大的基组和群等价物的应用。预测的基团等效气相生成热与实验的均方根偏差（rms）为3.2千卡/摩尔，最大偏差为6.5千卡/摩尔。预测的液体生成热的均方根和最大偏差分别为3.2和7.4千卡/摩尔。最后，预测的固体生成热的均方根和最大偏差分别为5.6和12.2千卡/摩尔，与早期Rice等人使用原子当量和较小基组（B3 LYP/6- 31 G *）的预测相比，均方根提高了约40%。
We present simple atom and group-equivalent methods that will convert quantum mechanical energies of molecules to gas phase heats of formation of CHNO systems. In addition, we predict heats of sublimation and vaporization derived from information obtained from the quantum-mechanically calculated electrostatic potential of each isolated molecule. The heats of sublimation and vaporization are combined with the aforementioned gas phase heats of fomation to produce completely predicted condensed phase heats of formation. These semiempirical computational methods, calibrated using experimental information, were applied to a series of CHNO molecules for which no experimental information was used in the development of the methods. These methods improve upon an earlier effort of Rice et al. [Rice, B. M.; Pai, S. V.; Hare, J. Combust. Flame 1999, 118, 445] through the use of a larger basis set and the application of group equivalents. The root-mean-square deviation (rms) from experiment for the predicted group-equivalent gas phase heats of formation is 3.2 kcal/mol with a maximum deviation of 6.5 kcal/mol. The rms and maximum deviation of the predicted liquid heats of formation are 3.2 and 7.4 kcal/mol, respectively. Finally, the rms and maximum deviation of predicted solid heats of formation are 5.6 and 12.2 kcal/mol, respectively, an improvement in the rms of approximately 40% compared to the earlier Rice et al. predictions using atom equivalents and a smaller basis set (B3LYP/6-31G*).