Unraveling the performance of dispersion-corrected functionals for the accurate description of weakly bound natural polyphenols

Long-range non-covalent interactions play a key role in the chemistry of natural polyphenols. We have previously proposed a description of supramolecular polyphenol complexes by the B3P86 density functional coupled with some corrections for dispersion. We couple here the B3P86 functional with the D3 correction for dispersion, assessing systematically the accuracy of the new B3P86-D3 model using for that the well-known S66, HB23, NCCE31, and S12L datasets for non-covalent interactions. Furthermore, the association energies of these complexes were carefully compared to those obtained by other dispersion-corrected functionals, such as B(3)LYP-D3, BP86-D3 or B3P86-NL. Finally, this set of models were also applied to a database composed of seven non-covalent polyphenol complexes of the most interest.FDM acknowledges financial support from the Swedish Research Council (Grant No. 621-2014-4646) and SNIC (Swedish National Infrastructure for Computing) for providing computer resources. The work in Limoges (IB and PT) is supported by the “Conseil Régional du Limousin”. PT gratefully acknowledges the support by the Operational Program Research and Development Fund (project CZ.1.05/2.1.00/03.0058 of the Ministry of Education, Youth and Sports of the Czech Republic). IB gratefully acknowledges financial support from “Association Djerbienne en France”

Accurate Treatment of Large Supramolecular Complexes by Double-Hybrid Density Functionals Coupled with Nonlocal van der Waals Corrections

In this work, we present a thorough assessment of the performance of some representative double-hybrid density functionals (revPBE0-DH-NL and B2PLYP-NL) as well as their parent hybrid and GGA counterparts, in combination with the most modern version of the nonlocal (NL) van der Waals correction to describe very large weakly interacting molecular systems dominated by noncovalent interactions. Prior to the assessment, an accurate and homogeneous set of reference interaction energies was computed for the supramolecular complexes constituting the L7 and S12L data sets by using the novel, precise, and efficient DLPNO-CCSD(T) method at the complete basis set limit (CBS). The correction of the basis set superposition error and the inclusion of the deformation energies (for the S12L set) have been crucial for obtaining precise DLPNO-CCSD(T)/CBS interaction energies. Among the density functionals evaluated, the double-hybrid revPBE0-DH-NL and B2PLYP-NL with the three-body dispersion correction provide remarkably accurate association energies very close to the chemical accuracy. Overall, the NL van der Waals approach combined with proper density functionals can be seen as an accurate and affordable computational tool for the modeling of large weakly bonded supramolecular systems.Financial support by the “Ministerio de Economía y Competitividad” (MINECO) of Spain and European FEDER funds through projects CTQ2011-27253 and CTQ2012-31914 is acknowledged. The support of the Generalitat Valenciana (Prometeo/2012/053) is also acknowledged. J.A. thanks the EU for the FP7-PEOPLE-2012-IEF-329513 grant. J.C. acknowledges the “Ministerio de Educación, Cultura y Deporte” (MECD) of Spain for a predoctoral FPU grant

Metallpulverspritzgießen bietet viele vorteile

Das MIM-Verfahren (Metal Injection Moulding; übersetzt: Metallpulverspritzgießen) ist ein hoch modernes Verfahren zur Herstellung metallischer Bauteile. Die Vorteile liegen in der Möglichkeit, sowohl geometrisch sehr komplexe Bauteile abzuformen, wie sie aus dem verwandten Kunststoffspritzgießen bekannt sind, als auch in der Freiheit der Materialauswahl. Selbst schwer zerspanbare Hochleistungswerkstoffe lassen sich vergleichsweise kostengünstig in Form bringen. Damit hat es die MIM-Technologie geschafft, sich in Industriezweigen wie Automobilbau, Medizintechnik, Anlagenbau, Luftfahrt und Consumer Goods zu etablieren

The rational design, synthesis and demonstration of the recognition and binding of a diaza-dioxa-12-crown-4 diphosphonate macrocycle to all crystal growth faces of barium sulfate

Computer-aided molecular design and virtual screening of a series of amino phosphonic acid derivatives were used to probe the probable interaction of these compounds as potential crystal growth inhibitors of barium sulfate, as judged by their ability to bind efficiently to all of the possible growing faces. As a result, a diphosphonic acid derivative of a 1,7-dioxa-4,10-diaza-12-crown-4 system 5 was proposed as a potential inhibitor of barium sulfate crystallisation. A subsequent synthesis of this macrocycle was developed, together with other larger-ring oxa-aza crown derivatives. Macrocycle 5 proved to be a highly efficient inhibitor of barium sulfate crystal growth at a level of 0.096 mM, as evidenced by the changes brought about in crystal morphology. Work was therefore undertaken to probe the mechanism of action of 5 using adsorption isotherms, mixed flow reactor and atomic force microscopy (AFM) measurements. It was possible to show that 5 inhibits effectively in solution by covering the growing surfaces, as observed on the 001 surface, effectively inhibiting two-dimensional nucleation as well as monolayer-step growth