Dynamic stabilization of perovskites at elevated temperatures: A comparison between cubic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>BaFeO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math> and vacancy-ordered monoclinic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>BaFeO</mml:mi><mml:mrow><mml:mn>2.67</mml:mn></mml:mrow></mml:msub></mml:math>

The impact of ordered vacancies on the dynamic stability perovskites is investigated under $\textit{ab initio}$ framework with a focus cubic BaFeO$_{3}$ ($Pm\bar{3}m$) and vacancy-ordered monoclinic BaFeO$_{2.67}$ ($P2_{1}/m$). harmonic approximation shows that both structures are dynamically unstable at 0 K. For structure, instability related to rotational distortions Fe coordination tetrahedra near vacancies. $\textit{Ab molecular dynamics simulations in combination introduced structural descriptor demonstrate stabilized above 130 Our results suggest do not significantly alter critical temperature which Ba$-$Fe$-$O stabilized. Further, strong anharmonicity for structure its revealed by significant asymmetry trajectories O anions