We present a novel and systematic fragmentation scheme to treat polycyclic aromatic hydrocarbons (PAHs) built off the molecules-in-molecules composite method. Our algorithm generates a set of biphenyl and naphthalene subsystems overlapping by whole sextet rings, ensuring all calculations are performed on aromatic molecules. Hence, our method is called Aromatic Fragmentation Based on a Ring Overlap Scheme (AroBOROS), and the generated fragments may be combined to form a hierarchy of subsystems to reduce errors for more complex PAHs. Errors are reduced to below chemical accuracy by combining subsystems that reflect the lowest energy structures determined by Clar's rule of aromatic sextets, and this is shown on two diverse test sets of PAHs ranging from 18 to 84 carbon atoms. Additionally, evaluations are performed for larger PAHs, as well as a nanotube fragment, containing up to 132 carbon atoms, and it is shown that good results may be achieved even with fragments representing an appreciably small portion of the full system.

中文翻译：

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基于环重叠方案的芳烃裂解：一种使用基于分子中分子裂解的方法的大型多环芳烃算法。

我们提出了一种新颖的系统化的裂解方案，以处理基于分子内复合方法构建的多环芳烃（PAH）。我们的算法生成了一组由整个六重环重叠的联苯和萘子系统，确保所有计算都在芳族分子上进行。因此，我们的方法称为基于环重叠方案的芳香碎片（AroBOROS），并且可以将生成的碎片进行组合以形成子系统的层次结构，以减少更复杂的PAH的错误。通过结合反映由Clar法则确定的最低能量结构的子系统，可将误差降低到化学精度以下，这在PAH的两个不同测试组中显示，其范围从18到84个碳原子。此外，还会对较大的PAH进行评估，