The structural, electronic, and magnetic properties of two-dimensional (2D) manganese dibromide (MnBr2) and manganese diiodide (MnI2) are investigated using first principles calculations. The dynamical and thermal stabilities of 2D MnBr2 and MnI2 have been illustrated from the phonon dispersion and molecular dynamic calculations. From the phonon dispersion, three Raman-active and three infrared-active vibration modes are found. The calculated formation energies and cleavage energies indicate that 2D MnBr2 and MnI2 are energetically stable and could be potentially obtained by exfoliation. The hybrid functional theory is employed to discover that 2D MnBr2 and MnI2 are wide gap semiconductors. The magnetic frustration is revealed by the calculation of magnetic exchange interaction and magnetocrystalline anisotropy interaction. By analyzing different magnetic orders, the relatively weak magnetic exchange is attributed to the competition of the direct exchange and the superexchange interaction.

中文翻译：

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基于第一性原理计算的新型二维 MnBr2 和 MnI2 的电学和磁学性质

使用第一性原理计算研究二维 (2D) 二溴化锰 (MnBr2) 和二碘化锰 (MnI2) 的结构、电子和磁性能。2D MnBr2 和 MnI2 的动力学和热稳定性已经从声子色散和分子动力学计算中得到了说明。从声子色散中，发现了三种拉曼活性和三种红外活性振动模式。计算的形成能和解理能表明 2D MnBr2 和 MnI2 在能量上是稳定的，可以通过剥离获得。使用混合泛函理论发现2D MnBr2 和MnI2 是宽能隙半导体。通过磁交换相互作用和磁晶各向异性相互作用的计算揭示了磁受挫。