First-principles studies on the charge density wave in uranium. (31st May 2016)

• Record Type: Journal Article
• Authors: Qiu, Ruizhi; Lu, Haiyan; Ao, Bingyun; Tang, Tao; Chen, Piheng
• Is Part Of: Modelling and simulation in materials science and engineering. Volume 24:Number 5(2016)
• Publication Date: 2016-05-31
• Subjects: first-principle studies -- uranium -- charge density wave -- crystal structure; Materials -- Mathematical models -- Periodicals; Matériaux -- Modèles mathématiques -- Périodiques; Materials -- Mathematical models; Periodicals; 620.00113
• DOI: 10.1088/0965-0393/24/5/055011
• Languages: English
• ISSNs: 0965-0393

Abstract

Abstract: The charge density wave (CDW) state of α -U (called α 1 -U) was studied through a first-principles total-energy minimization using the conjugate gradient algorithm. The optimized crystal structure of α 1 -U was found to have the space group Pbnm, which was proposed in the earlier Landau-type theory and is isostructural with the α -Np structure. In particular, the changes in the lattice parameters of Pbnm -U with respect to α -U are consistent with the experimental observations. In addition, the energetic stability of Pbnm -U with respect to α -U was confirmed by enthalpy calculations, and the value of the critical pressure in the pressure-induced quantum transition from Pbnm -U to α -U is in good agreement with the experimental result. Moreover, the phonon calculation verified the dynamical instability of α -U and the stability of Pbnm -U. Finally, the calculated electronic structures exhibit features of the CDW state.