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Two-dimensional transition metal dichalcogenides (TMDs) exhibit many novel properties due to dimension, lattice distortion, electron-electron interaction etc. Here, we determine that 1T-VTe 2 with space group P 3 ‾ m 1 is an antiferromagnetic metal by first-principles calculations, and three metastable structures are predicted, i.e., the P 21 / m and C 2 / m antiferromagnetic semiconductor phases and P 3 m 1 ferrimagnetic half-metal phase. Besides, the C 2 / m phase can be transfered to the P 3 m 1 phase by electron doping, while hole doping can induce a transition from C 2 / m phase to P 3 ‾ m 1 phase. These transitions could be ascribed to a strong coupling of charge, lattice, and spin degrees of freedom in VTe 2. The diverse electronic and magnetic properties of VTe2 provide a good platform for researchers to understand the interactions between spin, charge and lattice. • 1-VTe 2 is clarified to be antiferromagnetic metal ground state. • Three VTe 2 phases with different magnetic states and electronic structures are predicted. • Carrier doping can induce transitions between different phases. • Strong spin-lattice-charge interaction is found in VTe 2. [ABSTRACT FROM AUTHOR]

[Display omitted] Exploring new materials has attracted more and more attention, due to the improvement of technology and industry. Theoretically, the first-principles calculations combined with global optimization have been applied to predicting the properties of materials accurately and accelerate the discovery of new materials. For certain multi-component materials, the atoms are nearly at the lattice sites and the material exploration can be enhanced with biased screening. Based on the space symmetry, the calculations of duplicate structures can be avoided, and the specified constraints are applied to filter the energetically unstable candidates out. To provide the reasonable candidates for the first-principles calculations, we have released a program of Structures of Alloy Generation And Recognition (SAGAR), which can be conveniently used through the website. Herein, we will present several examples to show that the biased screening is practical and efficient, determining structures with high stabilities and novel properties. We have studied the distribution of up to 50% Cl vacancy concentration in NaCl and revealed semiconductor–metal transition in the boron/nitrogen co-doped diamond. The ground state anti-ferrormagnetic configuration of VCl 2 is determined, as well as the low-lying hydrogenated-C6 0 structures with high symmetry. Our results indicate that the biased screening with proper constraint will effectively enhance the material exploration. [ABSTRACT FROM AUTHOR]

Using density-functional theory calculations, we investigated the adsorption of transition-metal (TM) atoms (TM = Se, Ti, V, Cr, Mn, Fe, Co, and Ni) on carbon doped hexagonal boron nitride (BN) sheet and the corresponding cage (Bi2Ni2). With carbon substitution of nitrogen, Sc, V, Cr, and Mn atoms were energetically favorable to be dispersed on the BN nanostructures without clustering or the formation of TM dimers, due to the strong binding between TM atoms and substrate, which contains the half-filled levels above the valence bands maximum. The carbon doped BN nanostructures with dispersed Sc could store up to five and six H2, respectively, with the average binding energy of 0.3 ∼ 0.4 eV, indicating the possibility of fabricating hydrogen storage media with high capacity. We also demonstrated that the geometrical effect is important for the hydrogen storage, leading to a modulation of the charge distributions of d levels, which dominates the binding between H2 and TM atoms. [ABSTRACT FROM AUTHOR]