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首页> 外文期刊>Zeitschrift fur Arznei- und Gewurzpflanzen >Corrections of Molecular Morphology and Hydrogen Bond for Improved Crystal Density Prediction
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Corrections of Molecular Morphology and Hydrogen Bond for Improved Crystal Density Prediction

机译：用于改进晶体密度预测的分子形态和氢键的校正

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摘要

Density prediction is of great significance for molecular design of energetic materials, since detonation velocity linearly with density and detonation pressure increases with the density squared. However, the accuracy and generalization of former reported prediction models need further improvement, because most of them are derived from small data sets and few molecular descriptors. As shown in this paper, for molecules presenting brick-like shape or containing more hydrogen-bond donors the predicted densities have large negative deviations from experimental values. Thus, a molecular morphology descriptor eta and a hydrogen-bond descriptor H-b are introduced as correction items to build 3 new QSPR models. Besides, 3694 nitro compounds are adopted as data set by this work. The accuracies are obviously improved, and the generalizations are verified by an independent test set. At the level of B3PW91/6-31G(d,p), the effective ratios (ERs) of the 3 Equations, for Delta rho < 5%, are 92.7%, 91.8%, and 93.3%; for Delta rho < 2%, the values are 53.5%, 51.3%, and 54.7%. At the level of B3LYP/6-31G**, for Delta rho < 5%, the values are 92.3%, 91.4% and 92.9%; for Delta rho < 2%, the values are 53.7%, 51.4% and 53.2%.
机译：密度预测对于能量材料的分子设计具有重要意义，因为随着密度和爆炸压力线性的爆炸速度随着密度平方而增加。然而，前一种报告的预测模型的准确性和泛化需要进一步改进，因为大多数来自小数据集和少数分子描述符。如本文所示，对于呈现砖状形状或含有更多氢键供体的分子，预测密度具有与实验值的大负偏差。因此，将分子形态描述符ETA和氢键描述符H-B作为校正物品引入以构建3个新的QSPR模型。此外，3694个硝基化合物被采用作为这项工作设定的数据。精度得到改善，概括通过独立的测试集来验证。在B3PW91 / 6-31G（D，P）的水平下，3方程的有效比率（ERS）对于Delta Rho <5％，为92.7％，91.8％和93.3％;对于Delta Rho <2％，该值为53.5％，51.3％和54.7％。在B3LYP / 6-31G **的水平下，对于Delta rho <5％，值为92.3％，91.4％和92.9％;对于Delta Rho <2％，值为53.7％，51.4％和53.2％。

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