TY - JOUR
T1 - Lithium intercalation into TiO2(B)
T2 - A comparison of LDA, GGA, and GGA+U density functional calculations
AU - Morgan, Benjamin J.
AU - Madden, Paul A.
PY - 2012/7/27
Y1 - 2012/7/27
N2 - Density functional theory has been used to study lithium intercalation into TiO2(B) at low to moderate concentrations [0<x(Li)≤0.25] with a range of density functionals: LDA, GGA (PW91, PBE, PBEsol), and GGA+U (PBE+U, PBEsol+U), with the GGA+U calculations employing a Hubbard+U correction to the Ti d states. LDA and GGA functionals give the same general behavior, whereas qualitatively different behavior is predicted by GGA+U for electronic structure and the order of stability of occupied intercalation sites. LDA/GGA functionals predict LixTiO2(B) to be metallic, with the excess charge distributed over all the Ti sites. In contrast, GGA+U predicts defect states in the band gap corresponding to charge strongly localized at specific Ti sites. All the considered functionals predict A1 and/or A2 site occupation at x(Li)=0.25, which challenges the interpretation of previous neutron data that, at this composition, the C site is preferentially occupied.
AB - Density functional theory has been used to study lithium intercalation into TiO2(B) at low to moderate concentrations [0<x(Li)≤0.25] with a range of density functionals: LDA, GGA (PW91, PBE, PBEsol), and GGA+U (PBE+U, PBEsol+U), with the GGA+U calculations employing a Hubbard+U correction to the Ti d states. LDA and GGA functionals give the same general behavior, whereas qualitatively different behavior is predicted by GGA+U for electronic structure and the order of stability of occupied intercalation sites. LDA/GGA functionals predict LixTiO2(B) to be metallic, with the excess charge distributed over all the Ti sites. In contrast, GGA+U predicts defect states in the band gap corresponding to charge strongly localized at specific Ti sites. All the considered functionals predict A1 and/or A2 site occupation at x(Li)=0.25, which challenges the interpretation of previous neutron data that, at this composition, the C site is preferentially occupied.
UR - http://dx.doi.org/10.1103/PhysRevB.86.035147
U2 - 10.1103/PhysRevB.86.035147
DO - 10.1103/PhysRevB.86.035147
M3 - Article
SN - 1098-0121
VL - 86
JO - Physical Review B
JF - Physical Review B
IS - 3
M1 - 035147
ER -