174 research outputs found

    Maximally localized Wannier functions in LaMnO3 within PBE+U, hybrid functionals, and partially self-consistent GW: an efficient route to construct ab-initio tight-binding parameters for e_g perovskites

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    Using the newly developed VASP2WANNIER90 interface we have constructed maximally localized Wannier functions (MLWFs) for the e_g states of the prototypical Jahn-Teller magnetic perovskite LaMnO3 at different levels of approximation for the exchange-correlation kernel. These include conventional density functional theory (DFT) with and without additional on-site Hubbard U term, hybrid-DFT, and partially self-consistent GW. By suitably mapping the MLWFs onto an effective e_g tight-binding (TB) Hamiltonian we have computed a complete set of TB parameters which should serve as guidance for more elaborate treatments of correlation effects in effective Hamiltonian-based approaches. The method-dependent changes of the calculated TB parameters and their interplay with the electron-electron (el-el) interaction term are discussed and interpreted. We discuss two alternative model parameterizations: one in which the effects of the el-el interaction are implicitly incorporated in the otherwise "noninteracting" TB parameters, and a second where we include an explicit mean-field el-el interaction term in the TB Hamiltonian. Both models yield a set of tabulated TB parameters which provide the band dispersion in excellent agreement with the underlying ab initio and MLWF bands.Comment: 30 pages, 7 figure

    Interpolation in variable exponent spaces

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    In this paper we study both real and complex interpolation in the recently introduced scales of variable exponent Besov and Triebel–Lizorkin spaces. We also take advantage of some interpolation results to study a trace property and some pseudodifferential operators acting in the variable index Besov scale

    Variable exponent Besov-Morrey spaces

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    In this paper we introduce Besov-Morrey spaces with all indices variable and study some fundamental properties. This includes a description in terms of Peetre maximal functions and atomic and molecular decompositions. This new scale of non-standard function spaces requires the introduction of variable exponent mixed Morrey-sequence spaces, which in turn are defined within the framework of semimodular spaces. In particular, we obtain a convolution inequality involving special radial kernels, which proves to be a key tool in this work.publishe

    Sadržaj toksičnih i esencijalnih metala u ljekovitom bilju koje raste u onečišćenim i neonečišćenim područjima u Makedoniji

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    The aim of this study was to determine and compare Ba, Cr, Cd, Fe, Sr, Pb, and Zn content in medicinal herbs Urtica dioica L., Taraxacum officinale, and Matricaria recutita growing in polluted and unpolluted areas of the Republic of Macedonia. The metal content was determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). In the unpolluted area of Mt. Plačkovica the metal content in Taraxacum officinale was in the descending order: Fe>Sr>Zn>Ba>Cr, while Pb and Cd were below the limit of detection. In the polluted area of Veles, the order was as follows: Fe>Zn>Sr>Pb>Ba>Cd>Cr. Our results suggest that quality assurance and monitoring of toxic metals is needed for plants intended for human use and consumption. Medicinal plants should be picked in areas free of any contamination sources.Cilj je ovoga istraživanja bio utvrditi i usporediti sadržaj Ba, Cr, Cd, Fe, Sr, Pb i Zn u ljekovitom bilju Urtica dioica L., Taraxacum offi cinale i Matricaria recutita koje raste u onečišćenome odnosno neonečišćenome području u Republici Makedoniji. Sadržaj metala utvrdili smo s pomoću atomske emisijske spektroskopije induktivno spregnutom plazmom (engl. inductively coupled plasma atomic emission spectroscopy, krat. ICP-AES). U neonečišćenome području planine Plačkovice, sadržaj metala u Taraxacum offi cinale kretao se kako slijedi: Fe>Sr>Zn>Ba>Cr, dok su Pb i Cd bili ispod granice detekcije. U onečišćenome području blizu talionice olova i cinka u Velesu redoslijed je bio ovakav: Fe>Zn>Sr>Pb>Ba>Cd>Cr. Naši rezultati upućuju na potrebu za osiguranjem kakvoće i praćenjem razina toksičnih metala u biljaka namijenjenih ljudskoj uporabi. Ljekovito bilje valja brati u područjima bez izvora onečišćenja
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