Low-dimensional spin-1/2 transition metal oxides and oxyhalides continue to be at the forefront of research investigating nonclassical phases such as quantum spin liquids. In this study, we examine the magnetic properties of the oxyhalide ${\text{Cu}}_2{\text{(OH)}}_3\text{Br}$ in the botallackite structure using first-principles density functional theory, linear spin-wave theory, and exact diagonalization calculations. This quasi-two-dimensional system consists of ${\text{Cu}}^{2+}S=1/2$ moments arranged on a distorted triangular lattice. Our exact diagonalization calculations, which rely on a first-principles-based magnetic model, generate spectral functions consistent with inelastic neutron scattering data. By performing computational experiments to disentangle the chemical and steric effects of the halide ions, we find that the dominant effect of the halogen ions is steric in the ${\text{Cu}}_2{\text{(OH)}}_{3}X$ series of compounds.

中文翻译：

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Cu2（OH）3Br磁性的第一性原理表征

低维自旋1/2过渡金属氧化物和卤氧化物继续处于研究非经典相（例如量子自旋液体）的研究前沿。在这项研究中，我们研究了卤氧化物的磁性${\text{铜}}_2{\text{（哦）}}_3\text{溴}$使用第一原理密度泛函理论，线性自旋波理论和精确的对角化计算，对硼铁矿结构进行了研究。这个准二维系统由${\text{铜}}^{2+}\mathrm{小号}=\mathrm{1个}/2$矩排列在扭曲的三角形格子上。我们的精确对角化计算依赖于基于第一原理的磁模型，从而生成与非弹性中子散射数据一致的光谱函数。通过进行计算实验以解开卤化物离子的化学和空间效应，我们发现卤离子的主要作用是空间中的空间位阻。${\text{铜}}_2{\text{（哦）}}_{3}X$ 系列化合物。