We discuss the steady-state electronic transport in solid-state and molecular devices in the quantum regime. The decimation technique allows a comprehensive description of the electronic structure. Such a method is used, in conjunction with the generalizations of Landauer’s tunneling formalism, to describe a wide range of transport regimes. We analize mesoscopic and semiclassical metallic trans...

An approach to simulating warm and hot dense matter that combines density-functional-theory-based calculations of the electronic structure to classical molecular dynamics simulations with pair interaction potentials is presented. The method, which we call pseudoatom molecular dynamics, can be applied to single-component or multicomponent plasmas. It gives equation of state and self-diffusion co...

In this work, we have calculated the Joule-Thomson inversion curve of two important associating fluids, namely water and methanol, from the SAFT equation of state. Comparisons with the available experimental data, for water and methanol indicate that this molecular based equation of state gives good prediction of the low temperature branch; but, unfortunately, due to lack of isenthalpic dat...

A hybrid approach is described, which combines stochastic classical molecular dynamics and rst principles Density Functional theory to model the atomic and electronic structure of large molecular and solid-state systems. The stochastic molecular dynamics using Generalized Simulated Annealing (GSA) is based on the nonextensive statistical mechanics and thermodynamics. Examples are given of appli...

The photophysics of the 1-nitronaphthalene molecular system, after the absorption transition to the first singlet excited state, is theoretically studied for investigating the ultrafast multiplicity change to the triplet manifold. The consecutive transient absorption spectra experimentally observed in this molecular system are also studied. To identify the electronic states involved in the nonr...

The Mg(BiO2)2 is the orthorhombic crystal system acting as semiconductor in electric devices. To evaluate electronic band structures, the total density of state (TDOS) and the partial density of state (PDOS), Generalized Gradient Approximation (GGA) based on the Perdew–Burke–Ernzerhof (PBE0) was used for Mg(BiO2)2. The band gap was recorded at 0.959 eV, which is supported by a good semiconducto...

We show by means of ab initio calculations that the organic molecular crystal TTF-CA is multiferroic: it has an instability to develop spontaneously both ferroelectric and magnetic ordering. Ferroelectricity is driven by a Peierls transition of the TTF-CA in its ionic state. Subsequent antiferromagnetic ordering strongly enhances the opposing electronic contribution to the polarization. It is s...

III. Homonuclear Diatomics: Second-Row Elements 14 A. The diatomic boron molecule 16 1. Σg state 16 2. Σg state 19 B. The diatomic oxygen and carbon molecules in their lowest states 20 1. O2 20 2. Reflection symmetry 21 3. Electron repulsion 23 4. MCSCF calculations for O2 24 5. The C2 molecule 25 C. Spectroscopic notation for diatomic molecules 28 D. States of other homonuclear diatomic molecu...

A qualitative description of the electronic structure of single-wall carbon nanotubes from a chemical perspective is presented using real-space orbital representations and traditional concepts of aromaticity, orbital symmetry and frontier orbitals. This unusual view of carbon nanotubes allows us to merge the solid-state physics description of band structures with the molecular orbitals framewor...

Electronic absorption spectra of chrysophanol (1,8-dihydroxy-3-methylanthracene-9,10-dione), physcion (1,8-dihydroxy-3-methoxy-6-methylanthracene-9,10-dione) and emodin (1,3,8trihydroxy-6-methylanthracene-9,10-dione) were investigated. Molecular geometries of the substituted anthraquinones in the ground state were optimized using semiempirical AM1 method without imposing any symmetry constrains...