We present an atomistic theory of electronic transport through single organic molecules that reproduces the important features of the current-voltage ( I-V) characteristics observed in recent experiments. We trace these features to their origin in the electronic structure of the molecules and their local atomic environment. We demonstrate how conduction channels arise from the molecular orbital...

An ab initio Hartree-Fock approach aimed at directly obtaining the localized orthogonal orbitals (Wannier functions) of a crystalline insulator is described in detail. The method is used to perform all-electron calculations on the ground states of crystalline lithium fluoride and lithium chloride, without the use of any pseudo or model potentials. Quantities such as total energy, x-ray structur...

The Kugel-Khomskii Hamiltonian for cubic titanates describes spin and orbital superexchange interactions between d(1) ions having threefold degenerate t(2g) orbitals. Since orbitals do not couple along "inactive" axes, perpendicular to the orbital planes, the total number of electrons in |alpha> orbitals in any such plane and the corresponding total spin are both conserved. A Mermin-Wagner cons...

A novel derivation, involving the Fourier transform and the addition theorem of harmonic polynomials, is presented for multi-centre molecular integrals over spherical Gaussiantype orbitals. Compact closed-form formulae, consisting of vector-coupling coefficients and well known functions only, are obtained for all multi-centre molecular integrals. The resulting formulae manifest the angular and ...

The landmark 1954 J. Chem. Soc. paper by Craig et al. exploring the role of d-orbitals in chemical bonding is discussed. This paper set the agenda for discussions that continue until the present about topics in inorganic chemistry such as hypervalency, arguably the most significant bonding phenomenon to differentiate the chemistry of the 2p main group elements from their heavier congeners.

We present an overview of the existing localization algorithms which have been or are being used to perform quantum chemical molecular calculations that take into account electronic correlation effects. The natural distinction between intrinsic and extrinsic localization methods is explained and developed. The advantages and drawbacks of specific methods are discussed in terms of CPU time requi...