Open AccessFirst principles computational study on the stability of Li ion-vacancy two-dimensional ordered structures in intercalation compounds LixTiS2
Author(s) -
Qi Song,
Eindhoven Jiang,
Pei Hai-Lin,
Kang Jian-Hai,
Ying Guo
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.4817
Subject(s) - density functional theory , intercalation (chemistry) , vacancy defect , lattice (music) , computation , materials science , ion , lattice energy , stability (learning theory) , thermodynamics , condensed matter physics , crystal structure , computational chemistry , crystallography , physics , chemistry , mathematics , quantum mechanics , computer science , algorithm , acoustics , machine learning
Geometry optimization and total energy computation were carried out for TiS2, LiTiS2 and intercalation compound LixTiS2(x=1/4, 1/3, 1/2, 2/3, 3/4)ordered systems using first principles method based on local density approximation to density-functional theory. The computation results for these systems have been compared with other experimental and theoretical results available in the literature. The normalized increments of lattice parameters Δa0 and Δc0 increase monotonicly with the increasing concentration of Li ion. The curves show good agreement with lattice parameters obtained from experiment. The formation energies of ordered systems LixTiS2(x=1/4, 1/3, 1/2, 2/3, 3/4) are all negative, indicating their stability at low temperature. The formation energy of Li1/2TiS2 system with 3a0×a0 ordered structure is the lowest, implying the most stable structure. The results have shows that the local density approximation to density-functional theory can reasonably be applied to TiS2, LiTiS2 and intercalation compound LixTiS2(x=1/4, 1/3, 1/2, 2/3, 3/4)ordered systems.