Bond disproportionation, charge self-regulation, and ligand holes in s-p and in d-electron ABX(3) perovskites by density functional theory

Dalpian, G. M.1,2; Liu, Q.1,4; Varignon, J.3; Bibes, M.3; Zunger, Alex1

2018-08-20

10.1103/PhysRevB.98.075135

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

Some ABX(3)perovskites exhibit different local environments (DLE) for the same B atoms in the lattice, an effect referred to as disproportionation, distinguishing such compounds from common perovskites that have single local environments (SLE). The basic phenomenology associated with such disproportionation involves the absence of B-atom charge ordering, the creation of different B-X bond length ("bond alternation") for different local environments, the appearance of metal (in SLE) to insulator (in DLE) transitions, and the formation of ligand holes. We point out that this phenomenology is common to a broad range of chemical bonding patterns in ABX(3) compounds, either with s-p electron B-metal cations (BaBiO3, CsTlF3) or with noble-metal cations (CsAuCl3), as well as with d-electron cations (SmNiO3, CaFeO3). We show that underlying much of this phenomenology is the "self-regulating response," whereby in strongly bonded metal-ligand systems with high-lying ligand orbitals, the system protects itself from creating highly charged cations by transferring ligand electrons to the metal, thus preserving a nearly constant metal charge in different local environments, while creating B-ligand bond alternation and ligand-like conduction band ("ligand hole" states). We are asking what are the minimal theory ingredients needed to explain the main features of this SLE-to-DLE phenomenology, such as its energetic driving force, bond length changes, possible modifications in charge density, and density of state changes. Using as a guide the lowering of the total energy in DLE relative to SLE, we show that density functional calculations describe this phenomenology across the whole chemical bonding range without resort to special strong correlation effects, beyond what DFT naturally contains. In particular, lower total energy configurations (DLE) naturally develop bond alternation, gapping of the metallic SLE state, and absence of charge ordering with ligand hole formation.

SCI ; EI

英语

其他

DARI project EPOC[A0020910084]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000442194700002

AMER PHYSICAL SOC

PHYSICS

Web of Science

1.Univ Colorado, Renewable & Sustainable Energy Inst, Boulder, CO 80309 USA
2.Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP, Brazil
3.Univ Paris Saclay, Univ Paris Sud, Unite Mixte Phys, CNRS,Thales, F-91767 Palaiseau, France
4.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China

Dalpian, G. M.,Liu, Q.,Varignon, J.,et al. Bond disproportionation, charge self-regulation, and ligand holes in s-p and in d-electron ABX(3) perovskites by density functional theory[J]. PHYSICAL REVIEW B,2018,98(7).

Dalpian, G. M.,Liu, Q.,Varignon, J.,Bibes, M.,&Zunger, Alex.(2018).Bond disproportionation, charge self-regulation, and ligand holes in s-p and in d-electron ABX(3) perovskites by density functional theory.PHYSICAL REVIEW B,98(7).

Dalpian, G. M.,et al."Bond disproportionation, charge self-regulation, and ligand holes in s-p and in d-electron ABX(3) perovskites by density functional theory".PHYSICAL REVIEW B 98.7(2018).