Half-metallicity in materials has been a subject of extensive research due to its potential for applications in spintronics. Ferromagnetic manganites have been seen as a good candidate, and aside from a small minority-spin pocket observed in La(2-2x)Sr(1+2x)Mn(2)O(7) (x = 0.38), transport measurements show that ferromagnetic manganites essentially behave like half metals. Here we develop robust...

The Hückel (tight-binding) molecular orbital (HMO) method has found many applications in the chemistry of alternant conjugated molecules, such as polycyclic aromatic hydrocarbons (PAHs), fullerenes and graphene-like molecules, as well as in solid-state physics. In this paper, we found analytical expressions for the electron density matrix of the HMO method in terms of odd-powers of its Hamilton...

A self-consistent environment-dependent tight binding method is presented that was developed to simulate eigenvalue spectra, electron densities and Coulomb potential distributions for hydrocarbon systems. The method builds on a non-selfconsistent environment-dependent tight binding model for carbon [Tang et al., Phys. Rev. B 53, 979 (1996)] with parameters added to describe hydrocarbon bonds an...

D. R. Trinkle,1,2 M. D. Jones,3,2 R. G. Hennig,4 S. P. Rudin,2 R. C. Albers,2 and J. W. Wilkins4 1Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, Dayton, Ohio 45433-7817, USA 2Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 3State University of New York, Buffalo, New York 14260, USA 4Ohio State Univ...

We use a simple tight-binding model to study the magnetism of twodimensional quantum dot lattices with 1 to 12 electrons per dot. The results show that in the middle of an electron shell the lattice favours antiferromagnetism while with nearly empty or full shells ferromagnetism is favoured. The size of the antiferromagnetic region increases with the coordination number of the dot. A one-dimens...

Planar carbon-based electronic devices, including metal/semiconductor junctions, transistors and interconnects, can now be formed from patterned sheets of graphene. Most simulations of charge transport within graphene-based electronic devices assume an energy band structure based on a nearest-neighbour tight binding analysis. In this paper, the energy band structure and conductance of graphene ...

The dynamics of the driven tight binding model for Wannier-Stark systems is formulated and solved using a dynamical algebra. This Lie algebraic approach is very convenient for evaluating matrix elements and expectation values. It is also shown that a dynamical invariant can be constructed. A classicalization of the tight binding model is discussed as well as some illustrating examples of Bloch ...

Extensive urbanization has greatly raised the demand for cleaner coal- and petroleum-derived fuels. Mainly composed of methane, natural gas represents a promising alternative for this purpose, making its storage a significant topic. In the present research, deposition of methane molecules in C60 fullerene was investigated through a combined approach wherein density functional based tight bindin...

We develop a method and a computer code for the systematic optimization of a transferable tight-binding model for carbon-hydrogen compounds. We take as reference a density-functional theory calculation in the local density approximation and, using a «downhill simplex» routine, we minimize the squared difference between the energies predicted by the reference model and those obtained with our ti...

Semiconducting transition metal dichalcogenides present a complex electronic band structure with a rich orbital contribution to their valence and conduction bands. The possibility to consider the electronic states from a tight-binding model is highly useful for the calculation of many physical properties, for which first principle calculations are more demanding in computational terms when havi...