The repeated slab approach has become a de facto standard to accurately describe surface properties of materials by density functional theory calculations with periodic boundary conditions.For materials exhibiting spo...The repeated slab approach has become a de facto standard to accurately describe surface properties of materials by density functional theory calculations with periodic boundary conditions.For materials exhibiting spontaneous polarization,we show that the conventional scheme of passivation with pseudo hydrogen is unable to realize a charge-neutral surface.The presence of a net surface charge induces via Gauss’s law a macroscopic electric field through the slab and results in poor size convergence with respect to the thickness of the slab.We propose a modified passivation method that accounts for the effect of spontaneous polarization,describes the correct bulk limits and boosts convergence with respect to slab thickness.The robustness,reliability,and superior convergence of energetics and electronic structure achieved by the proposed method are demonstrated using the example of polar ZnO surfaces.展开更多
基金This work is supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy—EXC 2033—Projekt-nummer 390677874This project has received funding from the ECSEL Joint Undertaking(JU)project UltimateGaN under grant agreement No.826392The J.U.receives support from the European Union’s Horizon 2020 research and innovation program and Austria,Belgium,Germany,Italy,Slovakia,Spain,Sweden,Norway,Switzerland D.W.and C.Vd.W.were supported by the US Department of Energy(DOE),Office of Science,Basic Energy Sciences(BES)under award No.DE-SC0010689.
文摘The repeated slab approach has become a de facto standard to accurately describe surface properties of materials by density functional theory calculations with periodic boundary conditions.For materials exhibiting spontaneous polarization,we show that the conventional scheme of passivation with pseudo hydrogen is unable to realize a charge-neutral surface.The presence of a net surface charge induces via Gauss’s law a macroscopic electric field through the slab and results in poor size convergence with respect to the thickness of the slab.We propose a modified passivation method that accounts for the effect of spontaneous polarization,describes the correct bulk limits and boosts convergence with respect to slab thickness.The robustness,reliability,and superior convergence of energetics and electronic structure achieved by the proposed method are demonstrated using the example of polar ZnO surfaces.
