Structure and electronic properties of rare earth DOBDC metal–organic-frameworks. Issue 41 (11th October 2019)

• Record Type: Journal Article
• Authors: Vogel, Dayton J.; Sava Gallis, Dorina F.; Nenoff, Tina M.; Rimsza, Jessica M.
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 41(2019)
• Page Start: 23085
• Page End: 23093
• Publication Date: 2019-10-11
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp04038b
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Density functional theory is used to investigate rare-earth metal organic frameworks (MOFs) and characterize the level of theory needed to predict structural and electronic properties in MOF materials with 4f-electrons. Abstract : Here, we apply density functional theory (DFT) to investigate rare-earth metal organic frameworks (RE-MOFs), RE12 (μ3 -OH)16 (C8 O6 H4 )8 (C8 O6 H5 )4 (RE = Y, Eu, Tb, Yb), and characterize the level of theory needed to accurately predict structural and electronic properties in MOF materials with 4f-electrons. A two-step calculation approach of geometry optimization with spin-restricted DFT and large core potential (LCPs), and detailed electronic structures with spin-unrestricted DFT with a full valence potential + Hubbard U correction is investigated. Spin-restricted DFT with LCPs resulted in good agreement between experimental lattice parameters and optimized geometries, while a full valence potential is necessary for accurate representation of the electronic structure. The electronic structure of Eu-DOBDC MOF indicated a strong dependence on the treatment of highly localized 4f-electrons and spin polarization, as well as variation within a range of Hubbard corrections ( U = 1–9 eV). For Hubbard corrected spin-unrestricted calculations, a U value of 1–4 eV maintains the non-metallic character of the band gap with slight deviations in f-orbital energetics. When compared with experimentally reported results, the importance of the full valence calculation and the Hubbard correction in correctly predicting the electronic structure is highlighted.