1,720,969 research outputs found
Scripts: electrostatic integrals and Slater-Koster table derivatives, see dissertation, Gaussian Tight Binding Study of Ultrafast Electron Dynamics, for details.
No full textI offer here four independent scripts, written and tested with mathematica version 10.
1. klm.nb constructs the real cubic harmonics from the spherical harmonics Ylm(theta, phi) up to arbitrary order. The real cubic harmonics are further expressed in terms of the Cartesian coordinate system.
2. ddsk.nb defines the Slater-Koster matrix elements, and computes the first and second order derivatives, as well as their limits for R-> 0.
3. madelung.nb computes the analytical expressions for the primitive Cartesian-Gaussian electrostatic integrals, or Madelung integrals, and their derivatives.
4. electrostatic.nb computes numerically the electrostatic integrals, or Madelung integral
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Gaussian tight binding study of ultrafast electron dynamics
Full text linkComputer simulations are invaluable for the study of ultrafast phenomena, as it is not possible to directly access the electronic and nuclear dynamics in experiments. We present an efficient method for simulating the time-dependent coupled electron-ion dynamics within the Ehrenfest picture in molecules under the influence of time-dependent electric fields, based on an extension of the density-functional tight binding model. We consider self-consistency in a self-multipole-consistent framework, expanding the electron density in terms of radial Gaussian and angular real cubic harmonic functions. This enables the efficient computation of the electrostatic interaction energy while retaining a physical description of charge transfer and ionic polarisation. We show that this Gaussian tight binding method produces molecular polarisabilities, time-dependent dipole moments, and electron densities in strong agreement with density-functional theory, but at a small fraction of the cost. This efficiency enables high-throughput ultrafast studies on molecules, which we demonstrate on the example of transient core-spectroscopy on polythiophene fragments.Open Acces
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Data related to: Simulated TEM imaging of a heavily irradiated metal
No full text<p>Data set related to article "Simulated TEM imaging of a heavily irradiated metal"</p>
<p>The data is the output of a simulation of single-crystal tungsten with periodic boundary conditions evolving under irradiation up to high dose (1 dpa). The simulation was done in LAMMPS, only every 100th snapshot in LAMMPS Dump format is uploaded here. A frame corresponds to a dose increment of 0.000167 dpa, i.e. frame 1000 corresponds to a dose of 0.167 dpa. The files are zipped. A finer resolution can be supplied upon request.</p>
<p>The simulations were performed for the article: <a href="https://doi.org/10.1103/PhysRevMaterials.6.063601" target="_blank" rel="noopener">10.1103/PhysRevMaterials.6.063601</a>, where more details on the simulations are found. The data is here made available for the article: <a href="https://doi.org/10.48550/arXiv.2401.14781" target="_blank" rel="noopener">10.48550/arXiv.2401.14781</a>.</p>
<p>The TEM simulation software is available at: <a href="https://github.com/mason-daniel/simulated_tem">https://github.com/mason-daniel/simulated_tem</a>.</p>
- …
