We observe twofold shell filling in the spectra of closed one-dimensional quantum dots formed in single-wall carbon nanotubes. Its signatures include a bimodal distribution of addition energies, correlations in the excitation spectra for different electron number, and alternation of the spins of the added electrons. This provides a contrast with quantum dots in higher dimensions, where such spi...

Bond paths of maximum electron density spanning O-O edges shared between equivalent or quasiequivalent MOn (n > 4) coordination polyhedra are not uncommon electron density features displayed by silicates. On the basis of the positive values for the local electronic energy density, H(rc), at the bond critical points, rc, they qualify as weak "closed-shell" interactions. As observed for M-O bonde...

Different electronic configurations of a series of trinuclear heterometallic chains with 22 metallic electrons, MM'M(dpa)(4)X(2) (M = Co, Rh; M' = Ni, Pd; X = Cl, NCS), have been modelled in search of new systems with novel electrical properties. For this purpose, we explore the possibility of obtaining low-spin (extensively closed-shell) states by introducing chemical changes to the reference ...

An attempt is made to express the interaction energy in an endohedral A@B system starting from a one-center (r(<))(l)/(r(>))(l+1) expansion. Electrostatic, induction, and dispersion contributions are obtained from Rayleigh-Schrödinger perturbation theory. New electric polarizabilities with r(-l-1) radial integrals are calculated for l = 0, 1 and 2 for the outer system B. For a 'breakable'B, the...

While diabatic approaches are ubiquitous for the understanding of electron-transfer reactions and have been mooted as being of general relevance, alternate applications have not been able to unify the same wide range of observed spectroscopic and kinetic properties. The cause of this is identified as the fundamentally different orbital configurations involved: charge-transfer phenomena involve ...

The buckling analysis of stiffened cylindrical shells by rings and stringers made of functionally graded materials subjected to axial compression loading is presented. It is assumed that the material properties vary as a power form of the thickness coordinate variable. The fundamental relations, the equilibrium and stability equations are derived using the first order shear deformation theory. ...

The buckyferrocenes, synthesized through face-to-face fusion of ferrocene and fullerene fragments (C60Me10), are expected to enjoy the rich scientific heritage of ferrocene and fullerene with an extensively large π-conjugation network between the two Fe atoms [Y. Matsuo, K. Tahara and E. Nakamura, J. Am. Chem. Soc., 2006, 128, 7154]. However, the addition of pentamethyl groups at each end of th...

We study how the effect of closed-string tachyon condensation can enter into the on-shell effective action of open-string tachyons, for bosonic case. We also consider the open-string one-loop quantum corrections to the action. We use sigma-model approach with boundary terms, and we utilize some results of boundary string field theory (BSFT) to define the on-shell effective action. We regard D-i...

For a closed shell ground state with no neardegeneracy effects, a Hartree-Fock calculation followed by second-order many-body perturbation theory, MBPT2, provides reasonably accurate results at low cost in computer time. Hence, for a multireference second-order perturbation theory, we would like a method that reduces to the MBPT2 method for a single closed shell reference state and which retain...

Closed-shell BO(2)(-) and BO(-) anions are proposed as high-efficiency luminescence centres in boron-nitrogen systems, which makes the anions localized and leads to a radiation transition.