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用半经验量子化学方法(PM3和PM6)对56种含能材料分子的生成熟进行了计算。与实验结果相比,PM6法预测的生成热的均方根误差为10.62 kcal/mol,而PM3方法的均方根误差为14.06 kcal/mol。PM6方法所产生的平均无符号误差和平均误差均很小于相应的PM3结果。PM3计算结果与实验值的关系为:△_fH_(PM6)=0.9467△_fH_(Expt)+2.919,其线性回归系数R~2为0.9502。该方程可反过来用于校正含能材料的理论计算生成热。经校正后,56种含能材料分子的生成热PM6计算值的均方根误差减小至2.56 kcal/mol。此外,还求得DFT-B3LYP/6-31G*方法与PM6法的生成热计算结果之间的线性关系。当对生成热的精度要求不高时,半经验量子化学PM6法不失为又一种预测生成热的方法之一,特别适合于含能材料分子的高通量筛选。
The maturation of 56 energetic materials was calculated by semi-empirical quantum chemical methods (PM3 and PM6). Compared with the experimental results, the root mean square error (RMSE) of the heat of formation predicted by the PM6 method is 10.62 kcal / mol, while the root mean square error of the PM3 method is 14.06 kcal / mol. The average unsigned error and the average error produced by the PM6 method are much smaller than the corresponding PM3 results. The relationship between PM3 and experimental data is: △ _fH_ (PM6) = 0.9467 △ _fH_ (Expt) +2.919, and the linear regression coefficient R ~ 2 is 0.9502. This equation can in turn be used to correct theoretical calculations for the energetic material to generate heat. After correction, the root-mean-square error of the calculated PM6 values of 56 energetic materials decreased to 2.56 kcal / mol. In addition, the linear relationship between the DFT-B3LYP / 6-31G * method and the calculated heat of PM6 method is also obtained. The semi-empirical quantum chemical PM6 method is one of the methods to predict the heat of formation when the accuracy of the generated heat is not high enough. It is especially suitable for high-throughput screening of energetic material molecules.