All-electron GW calculation for molecules: Ionization energy and electron affinity of conjugated molecules

An efficient all-electron G$^0$W$^0$ method and a quasiparticle selfconsistent GW (QSGW) method for molecules are proposed in the molecular orbital space with the full random phase approximation. The convergence with basis set is examined. As an application, the ionization energy ($I$) and electron affinity ($A$) of a series of conjugated molecules (up to 32 atoms) are calculated and compared to experiment. The QSGW result improves the G$^0$W$^0$ result and both of them are in significantly better agreement with experimental data than those from Hartree-Fock (HF) and hybrid density functional calculations, especially for $A$. The nearly correct energy gap and suppressed self-interaction error by the HF exchange make our method a good candidate for investigating electronic and transport properties of molecular systems.Comment: 4 pages, 2 figures, 1 tabl

Achieving the Theoretical Depairing Current Limit in Superconducting Nanomesh Films

We show the theoretical depairing current limit can be achieved in a robust fashion in highly ordered superconductor nanomesh films having spatial periodicities smaller than both the superconducting coherence length and the magnetic penetration depth. For a niobium nanomesh film with 34 nm spatial periodicity, the experimental critical current density is enhanced by more than 17 times over the continuous film and is in good agreement with the depairing limit over the entire measured temperature range. The nanomesh superconductors are also less susceptible to thermal fluctuations when compared to nanowire superconductors. T_c values similar to the bulk film are achieved, and the nanomeshes are capable of retaining superconductivity to higher fields relative to the bulk. In addition, periodic oscillations in T_c are observed as a function of field, reflecting the highly ordered nanomesh structure

Scanning Tunneling Microscopy Characterization of the Electrical Properties of Wrinkles in Exfoliated Graphene Monolayers

We report on the scanning tunneling microscopy study of a new class of corrugations in exfoliated monolayer graphene sheets, that is, wrinkles ~10 nm in width and ~3 nm in height. We found such corrugations to be ubiquitous in graphene and have distinctly different properties when compared to other regions of graphene. In particular, a “three-for-six” triangular pattern of atoms is exclusively and consistently observed on wrinkles, suggesting the local curvature of the wrinkle provides a sufficient perturbation to break the 6-fold symmetry of the graphene lattice. Through scanning tunneling spectroscopy, we further demonstrate that the wrinkles have lower electrical conductance and are characterized by the presence of midgap states, which is in agreement with recent theoretical predictions. The observed wrinkles are likely important for understanding the electrical properties of graphene

A Systematic Identification and Analysis of Scientists on Twitter

Metrics derived from Twitter and other social media---often referred to as altmetrics---are increasingly used to estimate the broader social impacts of scholarship. Such efforts, however, may produce highly misleading results, as the entities that participate in conversations about science on these platforms are largely unknown. For instance, if altmetric activities are generated mainly by scientists, does it really capture broader social impacts of science? Here we present a systematic approach to identifying and analyzing scientists on Twitter. Our method can identify scientists across many disciplines, without relying on external bibliographic data, and be easily adapted to identify other stakeholder groups in science. We investigate the demographics, sharing behaviors, and interconnectivity of the identified scientists. We find that Twitter has been employed by scholars across the disciplinary spectrum, with an over-representation of social and computer and information scientists; under-representation of mathematical, physical, and life scientists; and a better representation of women compared to scholarly publishing. Analysis of the sharing of URLs reveals a distinct imprint of scholarly sites, yet only a small fraction of shared URLs are science-related. We find an assortative mixing with respect to disciplines in the networks between scientists, suggesting the maintenance of disciplinary walls in social media. Our work contributes to the literature both methodologically and conceptually---we provide new methods for disambiguating and identifying particular actors on social media and describing the behaviors of scientists, thus providing foundational information for the construction and use of indicators on the basis of social media metrics

Putting context into organizational intervention design:Using tailored questionnaires to measure initiatives for worker well-being

Realistic evaluation emphasizes the importance of exploring the mechanisms through which organizational interventions are effected. A well-known mechanism in organizational interventions is the screening process. Standardized questionnaires, in popular use, neither consider individuals’ appraisals of working conditions nor the specific context of the workplace. Screening with items tailored to intervention contexts may overcome the limitations of standardized questionnaires. In the present study, we evaluate an approach to develop a tailored questionnaire to measure employees’ appraisals of their specific working conditions. First, we interviewed 56 employees and 17 managers and, later, developed tailored items focused on the working conditions in a postal service. In follow-up interviews, we explore participants’ experiences with the tailored questionnaire, including the development of initiatives, compared to their previous experiences with the company´s annual attitude survey that used standardized scales. Results indicated that participants felt the tailored questionnaire highlighted issues that had previously been ignored, that initiatives were easier to develop due to its specificity, and that the feedback strategy was useful in prioritizing questionnaires. Overall, it can be concluded that tailored questionnaires may be appropriate for use in organizational intervention research and more broadly that evaluations of organizational interventions need to be contextually grounded

Molybdenum complexes derived from the oxydianiline [(2-NH₂C₆H₄)₂O] : synthesis, characterization and ε-caprolactone ROP capability

The reaction of Na₂MoO₄ with 2,2′-oxydianiline (2-aminophenylether), (2-NH₂C₆H₄)₂O, LH₄, in DME (DME = 1,2-dimethoxyethane) in the presence of Et₃N and Me₃SiCl afforded either the bis(imido) molybdenum(VI) complex {Mo(L)Cl₂(DME)} (1), where L = (2-NC₆H₄)₂O, or the molybdenum(V) salt [Mo(L′)Cl₄][Et₃NH] (2), where L′ = [(2-NH₂C₆H₄)(2-NC₆H₄)O], depending on the work-up method employed. The same diamine reacted with in situ [Mo(NtBu)₂Cl₂(DME)] afforded a tetra-nuclear complex [Mo₄Cl₃(NtBu)₃(OSiMe₃)(μ₄-O)(L)₂(L′)₂]·2MeCN (3·2MeCN). The crystal structures of 1, 2 and 3·2MeCN have been determined. The structure of the bis(imido) complex 1 contains two unique molecules paired up via weak π-stacking, whereas the structure of 2 contains a chelating amine/imido ligand, and is made up of discrete units of two cations and two anions which are interacting via H-bonding. The tetra-nuclear structure 3 contains four different types of distorted octahedral molybdenum centre, and a bent Me₃SiO group thought to originate from the precursor synthesis. Complexes 1–3 have been screened for their ability to ring open polymerize (ROP) ε-caprolactone. For 1 and 3 (not 2), conversion rates were good (>90%) at high temperatures (100 °C) over 6–24 h, and the polymerization proceeded in a living manner

Value stability and change during self-chosen life transitions: Self-selection versus socialization effects

Copyright @ 2013 APA. This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.Three longitudinal studies examine a fundamental question regarding adjustment of personal values to self-chosen life transitions: Do values fit the new life setting already at its onset, implying value-based self-selection? Or do values change to better fit the appropriate and desirable values in the setting, implying value socialization? As people are likely to choose a life transition partly based on their values, their values may fit the new life situation already at its onset, leaving little need for value socialization. However, we propose that this may vary as a function of the extent of change the life transition entails, with greater change requiring more value socialization. To enable generalization, we used 3 longitudinal studies spanning 3 different life transitions and different extents of life changes: vocational training (of new police recruits), education (psychology vs. business students), and migration (from Poland to Britain). Although each life transition involved different key values and different populations, across all 3 studies we found value fit to the life situation already early in the transition. Value socialization became more evident the more aspects of life changed as part of the transition, that is, in the migration transition. The discussion focuses on the implications of these findings for research on values and personality change, as well as limitations and future directions for research