Structural, electronic and magnetic properties of four transition metal tri-chalcogenide monolayers—MnPS 3 , MnPSe 3 , FePS 3 and FePSe 3 —are studied using density functional theory. Lattice structures in good agreement with experiments are obtained. Electronic structure of the Mn compounds obtained using the PBE-GGA functional is in qualitative agreement with the experiments, apart from the well known band gap problem. However, PBE fails for the Fe compounds. They turn out to be metallic, while experimentally they are characterized to be semiconductors. Inclusion of a Hubbard U term produces semiconducting states for both FePS 3 and FePSe 3 . We are able to produce the correct anti-ferromagnetic state for all the four compounds. This is significant because some previous calculations reported FePSe 3 to be non-magnetic. We obtain new insights into the bonding in these compounds through analyses of Bader ch...

中文翻译：

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密度泛函理论中MPX 3三卤化钨单层的电子结构：以四种化合物（M = Mn，Fe； X = S，Se）为例的研究

利用密度泛函理论研究了四种过渡金属三硫属元素化物单层的结构，电学和磁性。MnPS3，MnPSe 3，FePS 3和FePSe 3。获得与实验良好吻合的晶格结构。除了众所周知的带隙问题外，使用PBE-GGA官能团获得的Mn化合物的电子结构与实验定性一致。但是，PBE不能用于铁化合物。它们被证明是金属的，而在实验中它们被表征为半导体。包含Hubbard U项会产生FePS 3和FePSe 3的半导体状态。我们能够为所有四种化合物产生正确的反铁磁态。这很重要，因为以前的一些计算表明FePSe 3是非磁性的。