Recent photoelectron spectroscopy and computational studies have shown that boron ring–centered transition metal–doped inverse sandwich complexes prefer planar or quasi-planar structures which could be a potential building blocks for designing better nanosystems with tailored properties. Due to promising technological applications of different boron nanoclusters, we present a study on the structural, electronic, magnetic, and spectroscopic properties of Co-centered inverted sandwich monocyclic boron nanoclusters with pyramidal, CoB_n, and bi-pyramidal, Co₂B_n (n = 6–8) shapes. The investigations have been carried out on previously reported stable hexa-, hepta-, and octagonal hole containing pyramidal and bi-pyramidal boron clusters by employing density functional theory calculations with B3LYP hybrid exchange-correlation functional. Our calculation suggests that all the global minima structures have stable planar or quasiplanar symmetrical cyclic motif. The structural stability of clusters has been investigated by analyzing binding energy, thermodynamical parameters, vibrational spectra etc. All parameters indicate that the bi-pyramidal structures (Co₂B₆, Co₂B₇, and Co₂B₈) are more stable than both pristine and singly doped boron nanoclusters. On the contrary, the bi-pyramidal cluster is chemically less stable than the pyramidal clusters (except CoB₇) which is supported by the ionization potential, electron affinity, energy gap, and global indices calculations. Molecular electrostatic potential surface and HOMO-LUMO analysis have been carried out to understand the thermodynamically stable clusters that arises due to specific inter/intra-molecular interactions. The presence of magnetic element (Co) in the clusters induces ferromagnetic properties which have been found by investigating the magnetic moment, spin density, and DOS spectra analysis. Size and geometry-dependent properties of boron nanoclusters have been observed as evident from the energy gap and optical absorptions analysis.

中文翻译：

---

DFT研究反三明治单环硼纳米团簇ConBm（n = 1.2; m = 6-8）的几何结构，电子和光谱性质。

最近的光电子能谱和计算研究表明，以硼环为中心的过渡金属掺杂的反三明治复合物更喜欢平面或准平面结构，这可能是设计具有定制特性的更好纳米系统的潜在基础。由于不同硼纳米团簇的有前途的技术应用，我们目前对具有金字塔形CoB _n和双锥体Co ₂ B _n（以Co为中心的倒置三明治单环硼纳米团簇）的结构，电子，磁性和光谱性质进行了研究。ñ = 6–8）个形状。通过使用具有B3LYP杂化交换-相关函数的密度泛函理论计算，对先前报道的稳定的六，七和八角孔包含金字塔形和双金字塔形的硼簇进行了研究。我们的计算表明，所有全局最小值结构均具有稳定的平面或准平面对称循环图案。通过分析结合能，热力学参数，振动谱等研究了团簇的结构稳定性。所有参数均表明双锥体结构（Co ₂ B ₆，Co ₂ B ₇和Co ₂ B ₈）比原始的和单掺杂的硼纳米簇都更稳定。相反，双金字塔簇在化学上比金字塔簇不稳定（CoB ₇除外））受到电离势，电子亲和力，能隙和全局指数计算的支持。已经进行了分子静电势表面和HOMO-LUMO分析，以了解由于特定的分子间/分子间相互作用而产生的热力学稳定簇。团簇中磁性元素（Co）的存在会诱发铁磁性能，这是通过研究磁矩，自旋密度和DOS光谱分析发现的。从能隙和光吸收分析可以看出，硼纳米团簇的尺寸和几何形状依赖性。