Hyperfine coupling constants on inner‐sphere water molecules of GdIII‐based MRI contrast agents

[Abstract] Herein we present a theoretical investigation of the hyperfine coupling constants (HFCCs) on the inner‐sphere water molecules of [Gd(H2O)8]3+ and different GdIII‐based magnetic resonance imaging contrast agents such as [Gd(DOTA)(H2O)]−, [Gd(DTPA)(H2O)]2−, [Gd(DTPA‐BMA)(H2O)] and [Gd(HP‐DO3A)(H2O)]. DFT calculations performed on the [Gd(H2O)8]3+ model system show that both hybrid‐GGA functionals (BH&HLYP, B3PW91 and PBE1PBE) and the hybrid meta‐GGA functional TPSSh provide 17O HFCCs in close agreement with the experimental data. The use of all‐electron relativistic approaches based on the DKH2 approximation and the use of relativistic effective core potentials (RECP) provide results of essentially the same quality. The accurate calculation of HFCCs on the [Gd(DOTA)(H2O)]−, [Gd(DTPA)(H2O)]2−, [Gd(DTPA‐BMA)(H2O)] and [Gd(HP‐DO3A)(H2O)] complexes requires an adequate description of solvent effects. This was achieved by using a mixed cluster/continuum approach that includes explicitly two second‐sphere water molecules. The calculated isotropic 17O HFCCs (Aiso) fall within the range 0.40–0.56 MHz, and show deviations from the corresponding experimental values typically lower than 0.05 MHz. The Aiso values are significantly affected by the distance between the oxygen atom of the coordinated water molecule and the GdIII ion, as well as by the orientation of the water molecule plane with respect to the Gd‐O vector. 1H HFCCs of coordinated water molecules and 17O HFCCs of second‐sphere water molecules take values close to zero.Ministerio de Educación y Ciencia; CTQ2009‐10721Xunta de Galicia; IN845B‐2010/06

Die Esthernovelle, vom Erzählten zur Erzählung : Studien zur Traditions- und Redaktionsgeschichte des Estherbuches

Die in dieser Arbeit vorliegenden Studien zur Traditions- und Redaktionsgeschichte basieren auf der traditionsgeschichtlichen. Entscheidung, daβ die A-T.-Version des Esth der älteste Zeuge für den ursprünglichen Text des Esth darstellt. Auf der Basis dieses Textes und im Vergleich des A-T. mit den beiden anderen Versionen des Esth, dem M-T. und dem LXX-T., haben wir insgesamt drei dem Esth zugrundeliegende Erzählung herausgearbeitet. ... Zie: Zusammenfassung

Analytic Molecular Hessian Calculations for CC2 and MP2 Combined with the Resolution of Identity Approximation

An implementation of analytic second derivatives for the approximate coupled cluster singles and doubles model CC2 and for second-order Møller–Plesset perturbation theory (MP2) will be presented. The RI approximation for the two-electron repulsion integrals is used to reduce memory demands, operation count, and I/O requirements. During the calculation, the storage of N4 quantities (where N is a measure for the system size) can completely be avoided. It is shown that with the MP2 method and an appropriate scaling of the harmonic frequencies, especially C–F stretch frequencies are reproduced much better in comparison to experiments than with the B3LYP density functional. Similar advantages are observed for molecules with strong, internal van der Waals interactions. Spin scaling offers additional improvements in these cases. The implementation has been tested for molecules with up to 81 atoms and 684 basis functions