Screening in orbital-density-dependent functionals

Electronic-structure functionals that include screening effects, such as Hubbard or Koopmans' functionals, require to describe the response of a system to the fractional addition or removal of an electron from an orbital or a manifold. Here, we present a general method to incorporate screening based on linear-response theory, and we apply it to the case of the orbital-by-orbital screening of Koopmans' functionals. We illustrate the importance of such generalization when dealing with challenging systems containing orbitals with very different chemical character, also highlighting the simple dependence of the screening on the localization of the orbitals. We choose a set of 46 transition-metal complexes for which experimental data and accurate many-body perturbation theory calculations are available. When compared to experiment, results for ionization potentials show a very good performance with a mean absolute error of $~0.2$ eV, comparable to the most accurate many-body perturbation theory approaches. These results reiterate the role of Koopmans' compliant functionals as simple and accurate quasiparticle approximations to the exact spectral functional, bypassing diagrammatic expansions and relying only on the physics of the local density or generalized-gradient approximation

Modelling the Density of Inflation Using Autoregressive Conditional Heteroscedasticity, Skewness, and Kurtosis Models

The paper aimed at modelling the density of inflation based on time-varying conditional variance, skewness and kurtosis model developed by Leon, Rubio, and Serna (2005) who model higher-order moments as GARCH-type processes by applying a Gram-Charlier series expansion of the normal density function. Additionally, it extended their work by allowing both conditional skewness and kurtosis to have an asymmetry term. The results revealed the significant persistence in conditional variance, skewness and kurtosis which indicate high asymmetry of inflation. Additionally, diagnostic tests reveal that models with nonconstant volatility, skewness and kurtosis are superior to models that keep them invariant.inflation targeting, conditional volatility, skewness and kurtosis, modelling uncertainty of inflation

Design of Stocking Density of Broilers for Closed House in Wet Tropical Climates

The objectives of this research were to: 1) design the stocking density of broiler reared at a closed house system in wet tropical climates based on the heat released by broiler, 2) design broiler harvesting system based on the housing heat load, and 3) design required housing area based on the broiler age. The housing design used to determine the broiler stocking density was based on Computational Fluid Dynamics (CFD) with Solid Works Flow Simulation software. The method had good validation shown by small number of average percentage of deviation (6.07%). Simulation was carried out by changing the number of broilers i.e. 16, 18, 20, 21 and 22 birds/m2. According to the CFD simulation result, total heat load inside the house was 233.33 kW at 21 birds/m2 at weight 1.65 kg/bird. At that stocking density the housing can be occupied by 27,224 birds until 22 days of age. The highest total weight was produced by daily harvesting started from 22 to 32 d. It can be concluded that the stocking density of closed house for broiler is 34.65 kg/m2, total production is 45,717 kg per period and the required area for 27,224 broilers is 248.63 m2 (1 to 7 days of age broiler), 562.52 m2 (8 to 14 days of age broiler) and 1,000 m2 (15 to 22 days of age broiler)

Density of abortion facilities in the four largest US cities

Population Research Cente

Density of Zariski density for surface groups

We show that a surface group contained in a reductive real algebraic group can be deformed to become Zariski dense, unless its Zariski closure acts transitively on a Hermitian symmetric space of tube type. This is a kind of converse to a rigidity result of Burger, Iozzi and Wienhard

Density functional theory with adaptive pair density

We propose a density functional to find the ground state energy and density of interacting particles, where both the density and the pair density can adjust in the presence of an inhomogeneous potential. As a proof of principle we formulate an a priori exact functional for the inhomogeneous Hubbard model. The functional has the same form as the Gutzwiller approximation but with an unknown kinetic energy reduction factor. An approximation to the functional based on the exact solution of the uniform problem leads to a substantial improvement over the local density approximation

Loop corrections in spin models through density consistency

Computing marginal distributions of discrete or semidiscrete Markov random fields (MRFs) is a fundamental, generally intractable problem with a vast number of applications in virtually all fields of science. We present a new family of computational schemes to approximately calculate the marginals of discrete MRFs. This method shares some desirable properties with belief propagation, in particular, providing exact marginals on acyclic graphs, but it differs with the latter in that it includes some loop corrections; i.e., it takes into account correlations coming from all cycles in the factor graph. It is also similar to the adaptive Thouless-Anderson-Palmer method, but it differs with the latter in that the consistency is not on the first two moments of the distribution but rather on the value of its density on a subset of values. The results on finite-dimensional Isinglike models show a significant improvement with respect to the Bethe-Peierls (tree) approximation in all cases and with respect to the plaquette cluster variational method approximation in many cases. In particular, for the critical inverse temperature $\beta_{c}$ of the homogeneous hypercubic lattice, the expansion of $\left(d\beta_{c}\right)^{-1}$ around $d=\infty$ of the proposed scheme is exact up to the $d^{-4}$ order, whereas the two latter are exact only up to the $d^{-2}$ order.Comment: 12 pages, 3 figures, 1 tabl