Simultaneous optimization of crystal and magnetic structures: Applications to topological magnetic electrides

1.我们研究了分子晶体中的非晶相。通过第一性原理计算，我们证明了在准零维分子晶体中，借助于间隙电子，也可以实现非平凡的电子拓扑。我们明确展示了这种拓扑分子晶体的新特性，如多个可切割表面，对机械扰动的适度强烈响应，以及高质量的热电性。这项工作将晶格与分子晶体联系起来，突出了间隙电子在电子拓扑中的积极作用。我们将电子化合物的边界扩展到包括过渡金属化合物。过渡金属，如锰、铁、钴和镍，由于它们的非标准价态，传统上不被认为是氧化物中的良好阳离子候选物。然而，我们发现，由于过渡金属3d轨道的相关效应，间隙轨道可以稳定。我们发现，这种过渡金属氧化物表现出高功函数，表明它们与常规氧化物相比的稳定性。通过这一研究，我们可以看到电子关联和相变之间的相互作用。

1. We studied the electride phase in molecular crystals. By means of first-principles calculations, we showed that nontrivial electronic topology may be realized even in quasi-zero-dimensional molecular crystals, with the aid of interstitial electrons. We explicitly demonstrated the novel properties of such topological molecular crystals, such as multiple cleavable surfaces, moderately strong response to mechanical perturbations, and high-quality thermoelectricity. This work connects electrides with molecular crystals, and highlights the active role of interstitial electrons in electronic topology.2. We expanded the boundary of electrides to include transition metal compounds. Transition metals, like manganese, iron, cobalt, and nickel, are traditionally not considered as good cation candidates in electrides, on account of their nonstandard valence. However, we showed that the interstitial orbitals could be stabilized due to the correlation effects on transition metal 3d orbitals. We found that such transition metal electrides manifest a high work function, suggestive of their stability compared to conventional electrides. Through this study we can see the interplay between electron correlation and electride phases.