Search results for " set"
showing 10 items of 2095 documents
libvdwxc: A library for exchange-correlation functionals in the vdW-DF family
2017
We present libvdwxc, a general library for evaluating the energy and potential for the family of vdW-DF exchange--correlation functionals. libvdwxc provides an efficient implementation of the vdW-DF method and can be interfaced with various general-purpose DFT codes. Currently, the GPAW and Octopus codes implement interfaces to libvdwxc. The present implementation emphasizes scalability and parallel performance, and thereby enables \textit{ab initio} calculations of nanometer-scale complexes. The numerical accuracy is benchmarked on the S22 test set whereas parallel performance is benchmarked on ligand-protected gold nanoparticles ($\text{Au}_{144}(\text{SC}_{11}\text{NH}_{25})_{60}$) up to…
A Comparative Ab Initio Thermodynamic Study of Oxygen Vacancies in ZnO and SrTiO3: Emphasis on Phonon Contribution
2013
Using a hybrid Hartree–Fock (HF)-DFT method combined with LCAO basis set and periodic supercell approach, the atomic, electronic structure and phonon properties of oxygen vacancies in ZnO and SrTiO3 were calculated and compared. The important role of a ghost basis function centered at the vacant site and defect spin state for SrTiO3 is discussed. It is shown that the use of hybrid functionals is vital for correct reproduction of defects basic properties. The Gibbs free energy of formation of oxygen vacancies and their considerable temperature dependence has been compared for the two oxides. These calculations were based on the polarizability model for the soft mode temperature behavior in S…
Glass transition of hard spheres in high dimensions
2009
We have investigated analytically and numerically the liquid-glass transition of hard spheres for dimensions $d\to \infty $ in the framework of mode-coupling theory. The numerical results for the critical collective and self nonergodicity parameters $f_{c}(k;d) $ and $f_{c}^{(s)}(k;d) $ exhibit non-Gaussian $k$ -dependence even up to $d=800$. $f_{c}^{(s)}(k;d) $ and $f_{c}(k;d) $ differ for $k\sim d^{1/2}$, but become identical on a scale $k\sim d$, which is proven analytically. The critical packing fraction $\phi_{c}(d) \sim d^{2}2^{-d}$ is above the corresponding Kauzmann packing fraction $\phi_{K}(d)$ derived by a small cage expansion. Its quadratic pre-exponential factor is different fr…
Winning the hearts and minds of followers: The interactive effects of followers' emotional competencies and goal setting types on trust in leadership
2015
La confianza de los seguidores es un elemento esencial de un liderazgo eficaz. Las aproximaciones tempranas a la formación de la confianza hacia los líderes, adoptaron un enfoque basado en evaluaciones basadas en información. Sin embargo, avances recientes en la investigación de la confianza sugiere que estas evaluaciones también contienen un componente afectivo. En este estudio proponemos que las competencias emocionales, como (1) atención, (2) claridad y (3) reparación emocional predecirán la confianza hacia el líder en momentos tempranos de la relación líder-seguidor. A medida que esta relación se desarrolla en el tiempo, las evaluaciones sobre la fiabilidad del líder cambiaran su objeti…
¿Proveer justicia u oprimir a los pueblos? La acción de los corregedores de las Azores en el periodo moderno
2020
En Portugal, los corregedores han sido presentados por la historiografía tradicional como uno de los pilares del proceso de centralización política que había tenido lugar en el reino portugués a partir del final de la Edad Media. Esta interpretación ha sido corregida en las últimas décadas por nuevas investigaciones e interpretaciones. En los territorios portu- gueses de ultramar, la distancia amplió algunos de los “obstáculos fácticos” (según Antonio Manuel Hespanha) que hacían difícil, si no imposible, la concreción de cualquier proyecto centralizador. El caso azoriano es de esto un buen ejemplo. En este artículo, además de una síntesis de los poderes de los corregedores…
The Kuratowski convergence and connected components
2012
International audience; We investigate the Kuratowski convergence of the connected components of the sections of a definable set applying the result obtained to semialgebraic approximation of subanalytic sets. We are led to some considerations concerning the connectedness of the limit set in general. We discuss also the behaviour of the dimension of converging sections and prove some general facts about the Kuratowski convergence in tame geometry.
Separation properties of continuous maps in codimension 1 and geometrical applications
1992
Abstract Nuno Ballesteros, J.J. and M.C. Romero Fuster, Separation properties of continuous maps in codimension 1 and geometrical applications, Topology and its Applications 46 (1992) 107-111. We show that the image of a proper closed continuous map, f , from an n -manifold X to an ( n + 1)-manifold Y , such that H 1 (Y; Z 2 ) =0 , separates Y into at least two connected components provided the self-intersections set of f is not dense in any connected component of Y . We also obtain some geometrical applications.
A remark on weakly convex continuous mappings in topological linear spaces
2009
Abstract Let C be a compact convex subset of a Hausdorff topological linear space and T : C → C a continuous mapping. We characterize those mappings T for which T ( C ) is convexly totally bounded.
Elementary Newtonian Mechanics
2010
This chapter deals with the kinematics and the dynamics of a finite number of mass points that are subject to internal, and possibly external, forces, but whose motions are not further constrained by additional conditions on the coordinates. Constraints such as requiring some mass points to follow given curves in space, to keep their relative distance fixed, or the like, are introduced in Chap. 2. Unconstrained mechanical systems can be studied directly by means of Newton’s equations and do not require the introduction of new, generalized coordinates that incorporate the constraints and are dynamically independent. This is what is meant by “elementary” in the heading of this chapter — thoug…
Large time behavior for a porous medium equation in a nonhomogeneous medium with critical density
2014
Abstract We study the large time behavior of solutions to the Cauchy problem for the porous medium equation in nonhomogeneous media with critical singular density | x | − 2 ∂ t u = Δ u m , in R N × ( 0 , ∞ ) , where m > 1 and N ≥ 3 , with nonnegative initial condition u ( x , 0 ) = u 0 ( x ) ≥ 0 . The asymptotic behavior proves to have some interesting and striking properties. We show that there are different asymptotic profiles for the solutions, depending on whether the continuous initial data u 0 vanishes at x = 0 or not. Moreover, when u 0 ( 0 ) = 0 , we show the convergence towards a peak-type profile presenting a jump discontinuity, coming from an interesting asymptotic simplification…