In the context of ionic transport in solids, the variation of a migration barrier height under electric fields is traditionally assumed to be equal to the classical electric work of a point charge that carries the transport charge. However, how reliable is this phenomenological model and how does it fare with respect to Modern Theory of Polarization? In this work, we show that such a classical picture does not hold in general as collective dipole effects may be critical. Such effects are unraveled by an appropriate polarization decomposition and by an expression that we derive, which defines the equivalent polarization-work charge. The equivalent polarization-work charge is not equal neither to the transported charge, nor to the Born effective charge of the migrating atom alone, but it is defined by the total polarization change at the transition state. Our findings are illustrated by oxygen charged defects in MgO and in SiO₂.

在固体中离子迁移的情况下，传统上假定电场下迁移势垒高度的变化等于携带电荷的点电荷的经典电功。但是，这种现象学模型的可靠性如何？相对于现代极化理论，它的表现如何？在这项工作中，我们表明，这样的经典画面通常不会成立，因为集体偶极效应可能很关键。通过适当的极化分解以及我们得出的定义等效极化工作电荷的表达式，可以揭露此类影响。等效极化功电荷既不等于迁移原子，也不等于迁移原子的Born有效电荷，但它是由过渡状态下的总极化变化定义的。我们的发现可以通过MgO和SiO中的带氧缺陷来说明₂。