نتایج جستجو برای: lsda u

تعداد نتایج: 164987  

2001
Hua Wu

We have implemented a systematic LSDA and LSDA+U study of the double perovskites A2FeReO6 (A=Ba,Sr,Ca) and Sr2MMoO6 (M=Cr,Mn,Fe,Co) for understanding of their intriguing electronic and magnetic properties. The results suggest a ferrimagnetic (FiM) and half-metallic (HM) state of A2FeReO6 (A=Ba,Sr) due to a pdd-π coupling between the down-spin Re5+/Fe3+ t2g orbitals via the intermediate O 2pπ on...

2002
Julia E Medvedeva Vladimir I Anisimov Oleg N Mryasov Arthur J Freeman

Results of local spin-density approximation (LSDA) and LSDA+U calculations of the electronic structure and magnetic configurations of the 50% hole-doped pseudocubic perovskite La0.5Sr0.5MnO3 and double-layered LaSr2Mn2O7 are presented. We demonstrate that the on-site Coulomb correlation (U ) of Mn d electrons has a very different influence on the (i) band structures, (ii) magnetic ground states...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی شاهرود - دانشکده علوم پایه 1390

چکیده نظریه تابعی چگالی یکی از روش های بررسی دستگاه های بس ذره ای می باشد. معروفترین تقریب هایی که برای جمله تبادلی-همبستگی در نظریه تابعی چگالی استفاده می شوند، تقریب چگالی موضعی (lda) و تقریب شیب تعمیم یافته (gga) می باشند که در طیف وسیعی از مسایل جواب های قابل قبول و منطبق با نتایج تجربی را ارایه داده اند. اما این تقریب ها در توصیف دستگاه های همبسته قوی ضعیف عمل کرده و به نتایج منطبق با واق...

2012
S. J. Oh J. Hulliger Y. Tani K. Chikama

We report the electronic structure and optical properties of NdF3 compound. Our calculations are based on density functional theory (DFT) using the full potential linearized augmented plane wave (FPLAPW) method with the inclusion of spin orbit coupling. We employed the local spin density approximation (LSDA) and Coulomb-corrected local spin density approximation, known for treating the highly c...

Journal: :Physical review letters 2004
Peihong Zhang Weidong Luo Marvin L Cohen Steven G Louie

Doping evolution of the Fermi surface topology of Na(x)CoO(2) is studied systematically. Both local density approximation (LDA) and local spin density approximation (LSDA) predict a large Fermi surface as well as small hole pockets for doping levels x approximately 0.5. In contrast, the hole pockets are completely absent for all doping levels within LSDA+U. More importantly, we find no violatio...

2004
Xiangang Wan Masanori Kohno

By means of the LSDA+U method and the Green function method, we investigate the electronic and magnetic properties of the new material of Sr8CaRe3Cu4O24. Our LSDA+U calculation shows that this system is an insulator with a net magnetic moment of 1.01 μB/f.u., which is in good agreement with the experiment. Magnetic moments are mainly located at Cu atoms, and the magnetic moments of neighboring ...

Journal: :Physical review letters 2013
F Da Pieve S Di Matteo T Rangel M Giantomassi D Lamoen G-M Rignanese X Gonze

Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond density functional theory, we describe the magnetic ground state of Cr-doped TiO2, an intensively studied and debated dilute magnetic oxide. In parallel, we correct our LSDA+U (+ superexchange) ground state through GW corrections (GW@LSDA+U) that reproduce the position of the impurity st...

2003
H. Eschrig K. Koepernik

The LSDA+U approach to density functional theory is carefully reanalyzed. Its possible link to single-particle Green’s function theory is occasionally discussed. A simple and elegant derivation of the important sum rules for the on-site interaction matrix elements linking them to the values of U and J is presented. All necessary expressions for an implementation of LSDA+U into a non-orthogonal ...

در این مقاله با استفاده از تقریب های چگالی اسپین موضعی (LSDA) و چگالی اسپین موضعی بعلاوه انرژی هابارد (LSDA+U) در چارچوب نظریه تابعی چگالی ابتدا چگالی حالت های کل ، جزئی و همچنین گشتاور مغناطیسی اتم ها محاسبه و سپس با توجه به نتایج بدست آمده خواص الکترونی و مغناطیسی منگنایت NdMnO3 مطالعه شده است. محاسبه انرژی حالت پایه سیستم نشان داد فاز پایدار سیستم فرومغناطیس است. همچنین این بررسی نشان داد که...

2009
Diana Iuşan Mukul Kabir Oscar Grånäs Olle Eriksson Biplab Sanyal

Citation Iusan, Diana et al. " Microscopic picture of Co clustering in ZnO. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Density functional theory was applied t...

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