检索结果-内蒙古大学图书馆

Ferrimagnetic half Heusler alloys for waste heat recovery application- First principle study using different exchange-correlation functionals

引用

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 2023年第PartA期588卷

作者： Priyanka, D. . Shobana Sudharsan, J. B. Srinivasan, M. Elavarasan, N. Ramasamy, P. Fujiwara, K. SSN Coll Engn SSN Res Ctr Dept Phys Kalavakkam 603110 India Chennai Inst Technol Ctr Computat Modeling CCM Kundrathur 600069 India Tohoku Univ Inst Mat Res IMR 2-1-1 KatahiraAoba Ku Sendai 9808577 Japan

ZrMnSi and HfMnSi half Heusler alloys with magnetic ground state are investigated through density functional theory. The different exchange-correlation functionals (GGA, LDA, PBESol and WC) are used to study these alloys. The equilibrium lattice constants and corresponding ground state energies are calculated using these four approximation methods. From GGA functional, the obtained band gap for ZrMnSi is 1.268 eV and HfMnSi is 1.311 eV. The reported alloys are predicted to be half metals from different potentials, where those alloys show semiconductor character in minority spin channel and also exhibit metallic character in majority spin channel. The studied alloys are mechanically stable and ductile in nature. The total magnetic moment of -3 mu B is obtained in the reported ferrimagnetic alloys. The obtained thermoelectric figure of merit for ZrMnSi and HfMnSi is 0.46 at 1200 K and 0.31 at 1200 K respectively, it shows that these alloys are the potential candidates for waste heat recovery application, and they are also useful for spin flip device application.

关键词： Half Heusler alloys exchange-correlation functionals Ferrimagnetism Half metals Thermoelectric properties

来源：评论

学校读者我要写书评

暂无评论

Lattice parameters and bulk modulus of SrTi1-xMnxO3 perovskites: A comparison of exchange-correlation functionals with experimental validation

引用

COMPUTATIONAL CONDENSED MATTER 2025年 43卷

作者： Lebeda, Miroslav Drahokoupil, Jan Kamba, Stanislav Svoboda, Simon Smola, Vojtech Dabrowski, Bogdan Vlcak, Petr Czech Tech Univ FAC MECH ENGN DEPT PHYS TECHNICKA 4 PRAGUE 6 Czech Republic Czech Tech Univ Fac Nucl Sci & Phys Engn Dept Solid State Engn Trojanova 339 13 Prague 2 Czech Republic Czech Acad Sci Inst Phys Na Slovance 2 Prague 8 Czech Republic Polish Acad Sci Inst Phys Aleja Lotnikow 32 46 PL-02668 Warsaw Poland

We assessed four exchange-correlation functionals (LDA CA-PZ, GGA parametrized by PBE, PBEsol, and WC) in predicting the lattice parameters of SrTi1-xMnxO3 perovskites, assuming cubic structures. Predictions were verified using X-ray diffraction (XRD) for Mn content of x = 0.0, 0.1, 0.2, 0.3, 0.5, 1.0, confirming cubic symmetry and a linear decrease in lattice parameters with increasing Mn. PBEsol, and WC demonstrated the highest precision (deviations <0.20 %). Additionally, bulk moduli were calculated using the same functionals and verified with the experimental bulk modulus of SrTiO3 (183 +/- 2 GPa, Pulse-Echo method). The predicted bulk moduli exhibited a slow, linear increase with increasing Mn. The best correspondence with the experimental bulk modulus was achieved by PBEsol and WC (deviations <0.7 %). These findings highlight the reliability of PBEsol and WC functionals for accurately modeling structural properties of SrTi1-xMnxO3 perovskites, having better precision than commonly employed LDA and PBE functionals.

关键词： SrTi1-xMnxO3 perovskites exchange-correlation functionals Lattice parameters Bulk modulus

来源：评论

学校读者我要写书评

暂无评论

O2 on Ag(110): A puzzle for exchange-correlation functionals

引用

CHEMICAL PHYSICS 2022年 554卷 111424-111424页

作者： Loncaric, Ivor Alducin, Maite Inaki Juaristi, J. Rudjer Boskovic Inst Bijenicka 54 Zagreb 10000 Croatia Ctr Fis Mat CFM MPC CSIC UPV EHU Paseo Manuel de Lardizabal 5 Donostia San Sebastian 20018 Spain Donostia Int Phys Ctr DIPC Paseo Manuel de Lardizabal 4 Donostia San Sebastian 20018 Spain Univ Basque Country Dept Polimeros & Mat Avanzados Fis Quim & Tecnol Fac Quim Apartado 1072 Donostia San Sebastian 20080 Spain

Despite the great success of density functional theory in describing materials, there are still a few examples where current exchange-correlation functionals fail. We add another example to this list that drives further development of functionals. We show that the interaction of O-2 with Ag(110) cannot be properly described by some of the most popular GGA, meta GGA, and hybrid functionals. We identify problems and provide clues for a functional that should be able to describe this and similar systems properly.

关键词： Density functional theory exchange-correlation functionals

来源：评论

学校读者我要写书评

暂无评论

Structural and Electronic Calculations of CdTe Using DFT: exchange-correlation functionals and DFT-1/2 Corrections

引用

JOURNAL OF ELECTRONIC MATERIALS 2021年第4期50卷 2216-2222页

作者： Pochareddy, S. A. Nicholson, A. P. Thiyagarajan, A. Shah, A. Sampath, W. S. Colorado State Univ Dept Mech Engn Ft Collins CO 80523 USA Colorado State Univ Next Generat Photovolta Ctr Ft Collins CO 80521 USA

Ab initio calculations were performed to investigate the structural and electronic properties of bulk CdTe using various exchange-correlation (XC) functionals available. Among the selected XC functionals include the local density approximation (LDA), generalized gradient approximation (GGA), meta-generalized gradient approximation (MGGA) (using the linear combination of atomic orbitals basis scheme) and Heyd-Scuseria-Ernzerhof-06 (HSE06) (using the plane-wave basis scheme). Further computational studies were performed based on the local density approximation-1/2 (LDA-1/2) and generalized gradient approximation-1/2 (GGA-1/2) self-energy correction schemes to verify their effect on the CdTe band gap in comparison to the other traditional XC functionals. The lattice parameter values obtained using different XC functionals (LDA, GGA and MGGA) were well in agreement with experimental value, with LDA predicting 6.548 A. This is 1.02% greater than the experimental value of 6.482 A. The electronic structure of CdTe was calculated for the fixed 6.482 A lattice parameter of bulk CdTe and resulted in a band gap ranging between 0.68 and 1.56 eV for LDA, GGA, MGGA, and HSE06. The band gap values predicted by the LDA-1/2 and GGA-1/2 corrections were 1.47 eV and 1.50 eV, respectively, and are found to be in good agreement with experimental values. The influence of XC functionals and semi-empirical correction schemes are expected to have important implications on the prediction and understanding of bulk CdTe thin-films found in photovoltaic applications.

关键词： Density functional theory (DFT) LCAO plane-wave exchange energy correlation energy exchange-correlation functionals LDA GGA MGGA HSE06 DFT-1/2 Hartree potential pseudopotential

来源：评论

学校读者我要写书评

暂无评论

A comparative study of different exchange-correlation functionals in understanding structural, electronic and thermoelectric properties of Fe₂VAl and Fe₂TiSn compounds

引用

COMPUTATIONAL MATERIALS SCIENCE 2018年 143卷 316-324页

作者： Shastri, Shivprasad S. Pandey, Sudhir K. Indian Inst Technol Mandi Sch Engn Kamand 175005 India

Fe2VAl and Fe2TiSn are full Heusler compounds with non-magnetic ground state. The two compounds are good thermoelectric materials. PBE and LDA (PW92) are the two most commonly used density functionals to study the Heusler compounds. Along with these two well studied exchange-correlation functionals, recently developed PBEsol, mBJ and SCAN functionals are employed to study the two compounds. Using the five functionals equilibrium lattice parameter and bulk modulus are calculated. Obtained values are compared with experimental reports wherever available. Electronic structure properties are studied by calculating dispersion curves, total and partial density of states. For Fe2VAl, band gap of 0.22 eV is obtained from the mBJ potential which is in reasonable agreement with experimental value while, for Fe2TiSn band gap of 0.68 eV is obtained. Fe2VAl is predicted to be semimetallic with different values of negative gaps from LDA, PBEsol, PBE and SCAN functionals. Whereas, Fe2TiSn is found to be semimetallic (semiconducting) from LDA, PBEsol (PBE, SCAN) functionals employed calculations. From the dispersion curve effective mass values are also computed to see the contribution to the Seebeck coefficient. In Fe2TiSn, a flat band is present along the Gamma-X direction with calculated value of effective mass similar to 36 more than the mass of electron. The improvements or inadequacies among the functionals in explaining the properties of full Heusler alloys for thermoelectric application are thus observed through this study. (C) 2017 Elsevier B.V. All rights reserved.

关键词： exchange-correlation functionals Full Heusler alloys Electronic structure Effective mass Thermoelectric properties

来源：评论

学校读者我要写书评

暂无评论

van der Waals exchange-correlation functionals over bulk and surface properties of transition metals

引用

JOURNAL OF PHYSICS-CONDENSED MATTER 2019年第31期31卷 315501-315501页

作者： Avelar, Joana Bruix, Albert Garza, Jorge Vargas, Rubicelia Univ Autonoma Metropolitana Iztapalapa Dept Quim Div Ciencias Basicas & Ingn San Rafael Atlixco 186 Iztapalapa 09340 Ciudad De Mexic Mexico Aarhus Univ Interdisciplinary Nanosci Ctr iNANO Dept Phys & Astron DK-8000 Aarhus C Denmark Univ Munich Chair Theoret Chem Lichtenbergstr 4 D-85747 Garching Germany Univ Munich Catalysis Res Ctr Lichtenbergstr 4 D-85747 Garching Germany

The correct description of van der Waals (vdW) interaction forces is required for accurately describing dispersion bonded systems. Several approaches have been proposed to include London dispersion in density functional theory exchange-correlation functionals, where the family of so-called van der Waals (vdW-DF) exchange-correlation functionals have shown a better performance than local or semi local exchange-correlation functionals for describing molecular adsorption on metals. Despite the numerous benchmarks performed with these functionals, their performance in predicting bulk properties of transition metals has hitherto not been investigated in detail. We have therefore tested five vdW-DF exchange-correlation functionals, vdW-DF2, optPBE-vdW, BEEF-vdW, optB88-vdW and C09(x)-vdW to assess their performance in the prediction of lattice constants, bulk moduli, cohesive energies and surface energies of bulk Ni, Cu, Rh, Pd, Ag, Ir, Pt and Au (in fcc crystal structure). These transition metals are commonly used for benchmarking density functionals because they are important for applications in catalysis. The results are compared with experimental data and the PBE exchange-correlation functional. We found that both the optB88-vdW and the C09(x)-vdW exchange-correlation functionals estimate all properties with high accuracy, in better agreement with experimental data than PBE and other considered vdW functionals. The C09(x)-vdW functional clearly outperforms all other exchange-correlation functionals for surface energies for the (1 1 1) termination of different metals. We have also evaluated the interatomic electron density emerging from different functionals, and concluded that the observed differences are a result of the predicted lattice parameter, rather than a direct consequence of the functional form. Plane-wave and real-space grid-based expansions of the electron density are also compared, revealing good agreement between the two approaches for lattice parameters

关键词： transition metals exchange-correlation functionals electronic properties of solids energy surface of metals catalysis vdW interactions

来源：评论

学校读者我要写书评

暂无评论

Effect of exchange-correlation functionals on the density functional theory simulation of phase transformation of fast-ion conductors: A case study in the Li garnet oxide Li₇La₃Zr₂O₁₂

引用

COMPUTATIONAL MATERIALS SCIENCE 2017年 134卷 132-136页

作者： Klenk, Matthew J. Lai, Wei Michigan State Univ Dept Chem Engn & Mat Sci E Lansing MI 48824 USA

The phase transformation of a fast-ion conductor Li7La3Zr2O12 (LLZ) upon heating was investigated using first-principle molecular dynamics by applying the local density approximation (LDA) and thirteen generalized gradient approximations (GGA) of the electron exchange and correlation (XC) energy functionals within the density-functional theory (DFT) framework. It was found that some functionals in the selected group failed to predict the phase transformation behavior while others predicted too large or small lattice volumes. Of the fourteen, three functional types, PBEsol, SOGGA, and PBE2, exhibited behaviors consistent with the tetragonal to cubic phase transformation upon heating and they were able to reproduce crystallite volumes within 1.5% of the experimental values. The correlation of XC functional forms and their accuracy in predicting materials properties was discussed. (C) 2017 Elsevier B.V. All rights reserved.

关键词： exchange-correlation functionals Phase transformation Fast-ion conductors Lithium garnet oxide

来源：评论

学校读者我要写书评

暂无评论

Assessing accuracy of exchange-correlation functionals for electron affinities

引用

JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2017年第6期16卷 1750052-1750052页

作者： Pustula, Katarzyna Makowski, Marcin Jagiellonian Univ Fac Chem Dept Theoret Chem Ingardena 3 PL-30060 Krakow Poland

The performance of exchange-correlation (xc) functionals for the description of electron affinities of atomic and molecular systems is investigated. A benchmark set is constructed and experimental adiabatic electron affinities are compared to Density Functional Theory (DFT) predictions. The results show that although good overall accuracy may be achieved from DFT-based approaches, there still exist outliers for any of the approximations applied. Apart from employing the standard DFT models, the possibility of the optimization of range-separated xc functionals has also been tested, however, no large improvement in accuracy is observed.

关键词： Electron affinity benchmark exchange-correlation functionals

来源：评论

学校读者我要写书评

暂无评论

Assessing accuracy of exchange-correlation functionals for singlet-triplet excitations

引用

COMPUTATIONAL AND THEORETICAL CHEMISTRY 2015年 1060卷 52-57页

作者： Hanas, Martyna Makowski, Marcin Jagiellonian Univ Fac Chem Dept Theoret Chem PL-30060 Krakow Poland

The performance of exchange-correlation functionals for the description of the lowest-energy singlet-triplet excitations is investigated. The benchmark set of molecular triplet states is constructed and experimental data is compared to Density Functional Theory calculations. The accuracy of functionals is evaluated both in terms of adiabatic excitation energies and, where possible, reproduction of structural data and harmonic frequencies. The benchmark results show that for the selected group of functionals very good accuracy may be achieved and the quality of predictions provided is competitive to computationally more demanding coupled-cluster approaches. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Excited states Benchmark exchange-correlation functionals Triplets

来源：评论

学校读者我要写书评

暂无评论

Density functionals based on the mathematical structure of the strong-interaction limit of DFT

引用

WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2023年第2期13卷 e1634-e1634页

作者： Vuckovic, Stefan Gerolin, Augusto Daas, Timothy J. Bahmann, Hilke Friesecke, Gero Gori-Giorgi, Paola Inst Microelect & Microsyst CNR IMM Lecce Italy Vrije Univ Fac Sci Dept Chem & Pharmaceut Sci De Boelelaan 1083 NL-1081 HV Amsterdam Netherlands Vrije Univ Fac Sci Amsterdam Inst Mol & Life Sci AIMMS De Boelelaan 1083 NL-1081 HV Amsterdam Netherlands Univ Ottawa Dept Chem & Biomol Sci Ottawa ON Canada Univ Ottawa Dept Math & Stat Ottawa ON Canada Univ Wuppertal Phys & Theoret Chem Wuppertal Germany Tech Univ Munich Dept Math Munich Germany

While in principle exact, Kohn-Sham density functional theory-the workhorse of computational chemistry-must rely on approximations for the exchange-correlation functional. Despite staggering successes, present-day approximations still struggle when the effects of electron-electron correlation play a prominent role. The limit in which the electronic Coulomb repulsion completely dominates the exchange-correlation functional offers a well-defined mathematical framework that provides insight for new approximations able to deal with strong correlation. In particular, the mathematical structure of this limit, which is now well-established thanks to its reformulation as an optimal transport problem, points to the use of very different ingredients (or features) with respect to the traditional ones used in present approximations. We focus on strategies to use these new ingredients to build approximations for computational chemistry and highlight future promising directions. This article is categorized under: Electronic Structure Theory > Density Functional Theory

关键词： exchange-correlation functionals optimal transport theory strong electronic correlation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：