论文标题
部分可观测时空混沌系统的无模型预测
First-Principles investigation of the First-order Phase Transition in Kagome Na$_2$Ti$_3$Cl$_8$
论文作者
论文摘要
抗磁性kagome材料Na2ti3cl8表现出一阶相变；低温相的特征是Ti离子的修剪。在这项工作中，我们对高温和低温阶段的Na $ _2 $ _3 $ _3 $ cl $ _8 $的晶体和电子结构进行了第一原理计算。晶体结构，包括晶格常数和Ti离子的修剪，通过考虑1 eV的小哈伯德校正，可以很好地再现。计算出的总能量景观揭示了每公式单元80 MEV的一阶相变。对电子结构的分析表明，在修剪的低温相中，Ti之间的直接金属键合。
The antiferromagnetic kagome material Na2Ti3Cl8 exhibits a first-order phase transition; the low-temperature phase is characterized by the trimerizations of Ti ions. In this work, we carry out first-principles calculations on the crystal and electronic structure of Na$_2$Ti$_3$Cl$_8$ at the high- and low-temperature phases. The crystal structures, including the lattice constant and the trimerization of Ti ions, are well reproduced by taking account a small Hubbard correction of 1 eV. The calculated total energy landscape reveals a first-order phase transition with the total energy barrier of 80 meV per formula unit. Analysis of the electronic structure indicates a direct metal bonding among Ti in the trimierized low-temperature phase.
