SrFeO ${_3}$和LaFeO ${_3}$的扩散量子蒙特卡罗计算
Diffusion quantum Monte Carlo calculations of SrFeO${_3}$ and LaFeO${_3}$
摘要：
采用扩散量子蒙特卡罗（DMC）方法计算了SrFeO ${_3}$和LaFeO ${_3}$中氧空位的状态方程、形成能和迁移能垒。计算也进行了各种密度泛函理论（DFT）的近似比较。DMC再现了这些材料的内聚能测量误差低于0.23（5）eV和结构特性的实验值的1%以内。在富氧条件下，SrFeO ${_3}$和LaFeO ${_3}$中氧空位的DMC形成能分别为1.3（1）和6.24（7）eV。类似的计算与半本地DFT近似LaFeO $_3$产生的空位形成能量低1.5 eV。用DMC和DFT近似计算的电荷密度的比较表明，DFT倾向于过离域的电子在有缺陷的SrFeO ${_3}$和LaFeO ${_3}$。DMC和LDA的计算产生类似的空位迁移势垒，表明空间/静电效应主要决定这些材料中的迁移势垒。
英文摘要：
The equations of state, formation energy and migration energy barrier of the oxygen vacancy in SrFeO${_3}$ and LaFeO${_3}$ were calculated with the diffusion quantum Monte Carlo (DMC) method. Calculations were also performed with various Density Functional Theory (DFT) approximations for comparison. DMC reproduces the measured cohesive energies of these materials with errors below 0.23(5) eV and the structural properties within 1% of the experimental values. The DMC formation energies of the oxygen vacancy in SrFeO${_3}$ and LaFeO${_3}$ under oxygen-rich conditions are 1.3(1) and 6.24(7) eV, respectively. Similar calculations with semi-local DFT approximations for LaFeO$_3$ yielded vacancy formation energies 1.5 eV lower. Comparison of charge density evaluated with DMC and DFT approximations shows that DFT tends to overdelocalize the electrons in defected SrFeO${_3}$ and LaFeO${_3}$. Calculations with DMC and LDA yield similar vacancy migration energy barriers, indicating that steric/electrostatic effects mainly determine migration barriers in these materials.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
