A new polymorph of 5-nitrobenzo[c][1,2,5]thiadiazole, polymorph II, has been discovered. This polymorph is obtained by crystallization from solutions containing Cu(II) ions, which inhibit the formation of the already known polymorph I. The packings of the two polymorphs (actual crystal structures) are compared between each other and also with seven virtual polymorphs generated from the crystal structures of similar compounds retrieved from the CSD and optimized by ab initio calculations with periodic boundary conditions. The comparison is based on the analysis of the synthons present in the different crystal structures, and on calculated lattice energy and density. For the specific case examined, our analysis suggests that among crystal structures containing a given synthon, or a given combination of synthons, only the one with the lowest U_lat is observed; crystal structures with slightly higher U_lat (within 2 kcal mol⁻¹) can be observed, but they must be based on different synthons.

中文翻译：

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晶体能量景观之旅：多晶型 5-硝基苯并 [c][1,2,5] 噻二唑的实际和虚拟结构

已发现5-硝基苯并 [ c ][1,2,5] 噻二唑的新多晶型物，即多晶型物 II。这种多晶型物是通过从含有 Cu( II ) 离子的溶液中结晶获得的，它抑制了已知多晶型物 I 的形成。将两种多晶型物（实际晶体结构）的堆积相互比较，并与从中产生的七个虚拟多晶型物进行比较从 CSD 检索并通过从头算优化的类似化合物的晶体结构具有周期性边界条件的计算。比较基于对存在于不同晶体结构中的合成子的分析，以及计算的晶格能量和密度。对于所检查的具体情况，我们的分析表明，在包含给定合成子或给定合成子组合的晶体结构中，仅观察到U _{lat最低的那个；}可以观察到U _lat稍高（2 kcal mol ^-1以内）的晶体结构，但它们必须基于不同的合成子。