First principles investigation of the structure and electronic properties of Cu₂Te

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• 作者：Yinggan Zhang ; Baisheng Sa ; Jian Zhou ; Zhimei Sun
• 关键词：Transition-metal telluride ; Density functional theory ; Chemical bonding ; Electronic structure
• 刊名：Computational Materials Science
• 出版年：January, 2014
• 年：2014
• 卷：81
• 期：Complete
• 页码：163-169
• 全文大小：1591 K

文摘

By means of ab initio random structure search, we have revealed the crystal structure of Cu₂Te, which is in agreement with the experimentally proposed Nowotny鈥檚 model. We have then performed extensive calculations based on density functional theories (DFT) on this Cu₂Te structure. We have shown that the strong on-site Coulomb repulsion among the localized Cu 3d electrons has to be included via the addition of a proper U in order to describe the crystal structure precisely. Furthermore, the Te-Te bond in Cu₂Te shows the feature of van der Waals bonding, while the Cu-Te and Cu-Cu bonding are mainly strong covalent. By analyzing the density of states and electronic band structure, we have shown that Cu₂Te is a metallic conductor. Finally, the existence of a special Dirac-like cone at the K point in the electronic band structure of Cu₂Te reminisces that observed in graphene and topological insulators.