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

1. 我们研究了分子晶体中的电子相。通过第一性原理计算，我们证明了在间隙电子的帮助下，非平凡电子拓扑甚至可以在准零维分子晶体中实现。我们明确地展示了这种拓扑分子晶体的新特性，如多个可切割表面，对机械扰动的中等强响应，以及高质量的热电性。这项工作将电子与分子晶体连接起来，并突出了间隙电子在电子拓扑中的积极作用。我们扩大了电子化合物的范围，使其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，传统上不被认为是电子中良好的阳离子候选者。然而，我们发现由于过渡金属三维轨道的相关效应，间隙轨道可以稳定。我们发现这种过渡金属电子具有较高的功函数，表明它们与传统电子相比具有较高的稳定性。通过这项研究，我们可以看到电子相关和电子相之间的相互作用。

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.