Using time-dependent orbital-free density functional theory, we performed large-scale quantummechanical simulations to examine localized surface plasmon resonances in sodium nanorods. The dependence of the optical absorption wavelength, spectral width, and field enhancement on the dimensions of the nanorods, including the diameter, length, and aspect ratio as well as polarization direction, is examined for both longitudinal and tranverse plasmonic resonances. The longitudinal resonance is characterized by a dipolar charge oscillation with negligible charge spill-out from the surface, and its spectral wavelength is linearly related to the aspect ratio. The spectral width is found to be dependent on both the nanorod size and the aspect ratio, in contrast with previous classical results. The spectrum of the transverse plasmons is much wider than that of the longitudinal plasmons owing to the presence of multipolar oscillations and a strong electron spill-out effect. No linear relationship between the spectral wavelength and the aspect ratio is observed for the tranverse plasmons in which the electron spill-out effect is enhanced as the aspect ratio increases.

The stability, physical properties, and electronic structures of Cr(NCN)2 were studied using density functional theory with explicit electronic correlation (GGA+U). The calculated results indicate that Cr(NCN)2 is a ferromagnetic and half-metal, both thermodynamically and elastically stable. A comparative study on the electronic structures of Cr(NCN)2 and CrO2 shows that the Cr atoms in both compounds are in one crystallographically equivalent site, with an ideal 4+ valence state. In CrO2, the Cr atoms at the corner and center sites have different magnetic moments and orbital occupancies, moreover, there is a large difference between the intra- (12.1 meV) and inter-chain (31.2 meV) magnetic couplings, which is significantly weakened by C atoms in Cr(NCN)2.

The atomic-level structures of the icosahedral clusters in Cu–Zr–Al ternary metallic glasses were studied via the first-principles theory. The rules of icosahedra stability were determined. Icosahedra with a better chemical order or with a better symmetry exhibited a better stability. The strong connectivity between Al atom and Cu and Zr atoms was observed as demonstrated by the obvious degree of “bond shortening”. The Al atom contributed more to the structural stability when used as the central atom than the other atoms. Therefore, the addition of even a small amount of Al atom to the Cu–Zr binary system remarkably improved the stability of the icosahedron structures. The continued addition of Al atoms had a lower contribution to the improvement to the glass-forming ability of the Cu–Zr–Al alloys.