Orbital currents in the Colle-Salvetti correlation energy functional and the degeneracy problem

Popular density functionals for the exchange-correlation energy typically fail to reproduce the degeneracy of different ground states of open-shell atoms. As a remedy, functionals which explicitly depend on the current density have been suggested. We present an analysis of this problem by investigating functionals that explicitly depend on the Kohn-Sham orbitals. Going beyond the exact-exchange approximation by adding correlation in the form of the Colle-Salvetti functional we show how current-dependent terms enter the Colle-Salvetti expression and their relevance is evaluated. A very good description of the degeneracy of ground-states for atoms of the first and second row of the periodic table is obtained

Electric and Magnetic fields due to Dirac particles in FRW spacetime

Some solutions of the Maxwell equations with Dirac particles for the source in FRW spacetime are discussed. The Green's function of the equation for the radial component of the Maxwell fields, F_{r\eta} and F_{\theta\phi} is solved. Green's function is found to reduce to that of Minkowskian spacetime in the appropriate limit. Also, the Lienard-Wiechert type solution is derived. Also, the solutions with the Dirac particle current is also presented. It is found that the F_{r\eta} is composed of even angular momentum states while the odd states constitue F_{\theta\phi} .Comment: 8 pages including 2 figure

Spectral density and metal-insulator phase transition in Mott insulators within RDMFT

We present a method for calculating the spectrum of periodic solids within reduced density matrix functional theory. This method is validated by a detailed comparison of the angular momentum projected spectral density with that of well established many-body techniques, in all cases finding an excellent agreement. The physics behind the pressure induced insulator-metal phase transition in MnO is investigated. The driving mechanism of this transition is identified as increased crystal field splitting with pressure, resulting in a charge redistribution between the Mn $e_g$ and $t_2g$ symmetry projected states.Comment: arXiv admin note: text overlap with arXiv:0912.111

The Impact of Ethnicity on Cardiac Adaptation.

Regular intensive exercise is associated with a plethora of electrical, structural and functional adaptations within the heart to promote a prolonged and sustained increase in cardiac output. Bradycardia, increased cardiac dimensions, enhanced ventricular filling, augmentation of stroke volume and high peak oxygen consumption are recognised features of the athlete's heart. The type and magnitude of these adaptations to physical exercise are governed by age, sex, ethnicity, sporting discipline and intensity of sport. Some athletes, particularly those of African or Afro-Caribbean (black) origin reveal changes that overlap with diseases implicated in sudden cardiac death. In such instances, erroneous interpretation has potentially serious consequences ranging from unfair disqualification to false reassurance. This article focuses on ethnic variation in the physiological cardiac adaption to exercise

Reduced Density Matrix Functional for Many-Electron Systems

Reduced density matrix functional theory for the case of solids is presented and a new exchange correlation functional based on a fractional power of the density matrix is introduced. We show that compared to other functionals, this produces more accurate results for both finite systems. Moreover, it captures the correct band gap behavior for conventional semiconductors as well as strongly correlated Mott insulators, where a gap is obtained in absence of any magnetic ordering.Comment: 4 figs and 1 tabl

Non-collinear spin-spiral phase for the uniform electron gas within Reduced-Density-Matrix-Functional Theory

The non-collinear spin-spiral density wave of the uniform electron gas is studied in the framework of Reduced-Density-Matrix-Functional Theory. For the Hartree-Fock approximation, which can be obtained as a limiting case of Reduced-Density-Matrix-Functional Theory, Overhauser showed a long time ago that the paramagnetic state of the electron gas is unstable with respect to the formation of charge or spin density waves. Here we not only present a detailed numerical investigation of the spin-spiral density wave in the Hartree-Fock approximation but also investigate the effects of correlations on the spin-spiral density wave instability by means of a recently proposed density-matrix functional.Comment: 9 pages, 10 figure