We present a thorough density functional theory (DFT) based computational study of crystalline properties of cubane caged potential energetic material octonirocubane (ONC). As expected for a layered molecular solid, van der Waals (vdW) corrections are inevitable and the same has been incorporated to capture the ground state properties more accurately. Study of Born effective charge (BEC) and zone centered phonon frequencies using density functional perturbation theory (DFPT) reveals that important role of N2, N4 type nitrogen and associated oxygen atoms in contributing to the high intensity Infrared (IR) modes. From the calculated electronic band structure we can conclude that ONC is an insulator with a band gap of 5.31 eV. The optical properties of ONC are found to be nearly isotropic in low energy region in spite of strong anisotropic crystal structure.

中文翻译：

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从第一性原理理论研究含能材料八硝基立方烷的结构、弹性、振动和光学特性

我们提出了基于密度泛函理论 (DFT) 的全面计算研究，对立方笼潜在的高能材料 octonirocubane (ONC) 的晶体特性进行了计算研究。正如对分层分子固体所预期的那样，范德华 (vdW) 校正是不可避免的，并且已将其纳入以更准确地捕获基态特性。使用密度泛函微扰理论 (DFPT) 对波恩有效电荷 (BEC) 和区域中心声子频率的研究揭示了 N2、N4 型氮和相关氧原子在促成高强度红外 (IR) 模式中的重要作用。根据计算出的电子能带结构，我们可以得出结论，ONC 是一种带隙为 5.31 eV 的绝缘体。