1We present a comprehensive investigation, via first-principles density functional theory 2 (DFT) calculations, of various surface terminations of magnetite, Fe 3 O 4 (111), a major 3 iron oxide which has also a number of applications in electronics and spintronics. We 4 compare the thermodynamic stability and electronic structure among the different 5 surfaces terminations. Interestingly, we find that surfaces modified with point defects 6and adatoms are close in surface energy and in the oxygen-rich and oxygen-poor 7 regimes can be more stable than bulk-like terminations. These surfaces show different 8 surface chemistry and electronic structures as well as distinctive spin polarization 9 features near the Fermi level with regard to those previously considered in the literature. 10 Our studies provide an atomic level insight for magnetite surfaces, which is a necessary 11 step to understanding their interfaces with organic layers in OLED and spintronic 12 devices. 13

Long-range corrected hybrid density functionals (LC-DFT), with range separation parameters optimally tuned to obey Koopmans' theorem, are used to calculate the firstorder hyperpolarizabilities of prototypical charge-transfer compounds p-nitroaniline (PNA) and dimethylamino nitrostilbene (DANS) in gas phase and various solvents.It is shown that LC-DFT methods with default range separation parameters tend to * To whom correspondence should be addressed between the hyperpolarizability and amount of exact exchange, and thus this behavior may serve as a diagnostic tool for the adequacy of LC-DFT.

We present the results of density functional theory (DFT) calculations on magnetite, Fe3O4, which has been recently considered as electrode in the emerging field of organic spintronics. Given the nature of the potential applications, we evaluated the magnetite room-temperature cubic phase in terms of structural, electronic, and magnetic properties. We considered GGA (PBE), GGA + U (PBE + U), and range-separated hybrid (HSE06 and HSE(15%)) functionals. Calculations using HSE06 and HSE(15%) functionals underline the impact that inclusion of exact exchange has on the electronic structure. While the modulation of the band gap with exact exchange has been seen in numerous situations, the dramatic change in the valence band nature and states near the Fermi level has major implications for even a qualitative interpretation of the DFT results. We find that HSE06 leads to highly localized states below the Fermi level while HSE(15%) and PBE + U result in delocalized states around the Fermi level. The significant differences in local magnetic moments and atomic charges indicate that describing room-temperature bulk materials, surfaces and interfaces may require different functionals than their low-temperature counterparts.

Solvent-assisted linker exchange (SALE) has recently emerged as an attractive strategy for the synthesis of metal-organic frameworks (MOFs) that are unobtainable via traditional synthetic pathways. Herein we present the first example of selective SALE in which only the benzimiadazolate-containing linkers in a series of mixed-linker zeolitic imidazolate frameworks (ZIF-69, -78, and -76) are replaced. The resultant materials (SALEM-10, SALEM-10b, and SALEM-11, respectively) are isostructural to the parent framework and in each case contain trifluoromethyl moieties. We therefore evaluated each of these materials for their hydrophobicity in condensed and gas phases. We expect that selective SALE will significantly facilitate the design of improved, and potentially complex, MOF materials with new and unusual properties.

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