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The first-principles calculation on the crystal and electronic structures of a lithium insertion material of LiCo 1/3 Ni 1/3 Mn 1/3 O 2 has been carried out to search new positive-electrode materials for advanced lithium-ion batteries. LiCo 1/3 Ni 1/3 Mn 1/3 O 2 having a superlattice based on an ␣-NaFeO 2 -type structure is suggested to be stable. According to the calculations, formal charges of Co, Ni, and Mn in LiCo 1/3 Ni 1/3 Mn 1/3 O 2 ( P3 1 12, a ϭ 4.904 Å, c ϭ 13.884 Å͒ are, respectively, estimated to be ϩ3, ϩ2, and ϩ4. The solid-state redox reactions of LiCo 1/3 Ni 1/3 Mn 1/3 O 2 are investigated under the assumption of a lithium insertion scheme, and the reactions are shown to be formally Ni 2ϩ /Ni 3ϩ for 0 р x р 1/3 in Li 1Ϫx Co 1/3 Ni 1/3 Mn 1/3 O 2 , Ni 3ϩ /Ni 4Ϫ for 1/3 р x р 2/3 and Co 3ϩ /Co 4ϩ for 2/3 р x р 1. Manganese ions do not participate for the redox reactions in an entire range. The illustrated maps on the change in electron density for the solid-state redox reactions indicate that the charge balance is due to the loss or gain of electrons on oxygen ions while the redox centers are transition metal ions of Ni or Co. Reversible potentials of Li 1Ϫx Co 1/3 Ni 1/3 Mn 1/3 O 2 against a lithium electrode are also calculated and the possibility of implementation is discussed with respect to the computational chemistry based on the first-principles calculation.

A totally nonempirical relativistic cluster calculation of transition-metal L 2,3 -edge x-ray-absorption nearedge structure including configuration interaction has been performed. A remarkable predictive power of this calculation has been demonstrated for three contrasting materials with different d-electron numbers and different coordination numbers ͑SrTiO 3 , NiO, and CaF 2 ͒ by excellent reproduction of both the absolute peak energies and their relative intensities without any empirical parameters.