Research report Fluoride 53(4):657-667 October-December 2020 First principle study of the properties of cubic fluoroperovskites Husain, Ahmad, Rahman, Sajjad, Rauf, Habib, Ul Haq, Nisar, Hussain, Imran, Salahuddin 657 657 [Now published in full after the initial publication as an Epub ahead of print on June 29, 2020 at. www.fluorideresearch.online/epub/files/087.pdf] FIRST PRINCIPLE STUDY OF THE STRUCTURAL, ELECTRONIC, AND MECHANICAL PROPERTIES OF CUBIC FLUOROPEROVSKITES: (ZnXF 3 , X = Y, Bi) Mudasser Husain, a Muhammad Salman Ahmad, b Nasir Rahman, c, * Muhammad Sajjad, a Abdur Rauf, d Anwar Habib, a Mahmood Ul Haq, e Mohammad Nisar, e Akhlaq Hussain, e Muhammad Imran, e Salahuddin e Kohat and Islamabad, Pakistan, and Sichuan, Zhenjiang, and Nanjing, People’s Republic of China ABSTRACT: In the scheme of density functional theory (DFT) and by means of the full- potential linearized augmented plane wave process within the generalized gradient approximation, the structural, electronic and elastic properties of ZnXF 3 (X = Y, Bi) were investigated for the first time. The structural parameters for each compound were observed to be consistent to those reported in the literature. It is observed that both of the compounds had a narrow band gap and that one of the compounds (ZnBiF 3 ) had a direct band gap of 0.5 eV from (M-M), while the other one (ZnYF 3 ) had an indirect band gap from (M-X) of 1.95 eV. The total electronic properties of ZnXF 3 (X = Y, Bi) were mainly controlled by the Zn atom, while in the partial electronic properties and the density of states the major contribution came from the Zn-d state and a minor contribution came from the F-p state. For the elastic properties, calculations were made of the elastic constants, the shear modulus, the anisotropy factor, Young’s modulus, and the Poisson ratio was calculated. The results indicated that the present compounds were ductile and mechanically stable. The above investigations give a comprehensive insight into how these compounds may be used in designing high performance electronic devices. Keywords: Cubic fluoroperovskites; Elastic properties; FP-LAPW method; Structural properties. 1. INTRODUCTION Fluoroperovskite compounds have received an immense consideration owing to their remarkable physical and structural properties, 1 such as piezo-electricity, 2 ferromagnetism, 3 photoluminescence, 4,5 colossal magneto-resistivity, and high temperature superconductivity. 6 Fluoro-perovskites like AgMgF 3 and AgZnF 3 were investigated previously by focusing on their structural properties to calculate their lattice constants and tolerance factors, by means of various analytical approaches. 7-9 Other material properties, such as electronic, optical, and chemical bonding, were not given much attention. Murtaza et al. investigated the structural and opt-electronic properties of similar compounds, namely AgTF 3 (T = Mg, Zn), by the full-potential linearized augmented plane wave technique incorporated within the generalized gradient approximation. 10 The mechanical properties of such fluoroperovskite compounds still need to be investigated. Among these fluoroperovskite compounds, the structural, electronic, elastic, and other physical properties of ZnXF 3 (X = Y, Bi) have, so far, not been studied, either theoretically or experimentally. a Department of Physics, Kohat University of Science & Technology, Kohat 26000, Pakistan; b School of Political Science and Public Administration, Neijiang Normal University, Sichuan, People’s Republic of China; c School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, People’s Republic of China; d Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, People’s Republic of China; e School of Material Science and Engineering, Zhejiang University, People’s Republic of China; f Materials Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad, Pakistan. For correspondence: Dr Nasir Rahman, School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, People’s Republic of China; E-mail: rahman_phy@yahoo.com