Multiwfn is a multifunctional program for wavefunction analysis. Its main functions are: (1) Calculating and visualizing real space function, such as electrostatic potential and electron localization function at point, in a line, in a plane or in a spatial scope. (2) Population analysis. (3) Bond order analysis. (4) Orbital composition analysis. (5) Plot density-of-states and spectrum. (6) Topology analysis for electron density. Some other useful utilities involved in quantum chemistry studies are also provided. The built-in graph module enables the results of wavefunction analysis to be plotted directly or exported to high-quality graphic file. The program interface is very user-friendly and suitable for both research and teaching purpose. The code of Multiwfn is substantially optimized and parallelized. Its efficiency is demonstrated to be significantly higher than related programs with the same functions. Five practical examples involving a wide variety of systems and analysis methods are given to illustrate the usefulness of Multiwfn. The program is free of charge and open-source. Its precompiled file and source codes are available from http://multiwfn.codeplex.com.

Multiwfn: a multifunctional wavefunction analyzer.

Self-Assembly of Discrete Cyclic Nanostructures Mediated by Transition Metals

The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century 1 organic chemists have sought to develop new and more efficient aryl -aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl -aryl bonds, arguably the most common method is through the use of transition-metalmediated reactions. 2-4 While earlier reports focused on the use of stoichiometric quantities of a transition metal to carry out the desired transformation, modern methods of transitionmetal-catalyzed aryl -aryl coupling have focused on the development of high-yielding reactions achieved with excellent selectivity and high functional group tolerance under mild reaction conditions. Typically, these reactions involve either the coupling of an aryl halide or pseudohalide with an organometallic reagent (Scheme 1), or the homocoupling of two aryl halides or two organometallic reagents. Although a number of improvements have developed the former process into an industrially very useful and attractive method for the construction of aryl -aryl bonds, the need still exists for more efficient routes whereby the same outcome is accomplished, but with reduced waste and in fewer steps. In particular, the obligation to use coupling partners that are both activated is wasteful since it necessitates the installation and then subsequent disposal of stoichiometric activating agents. Furthermore, preparation of preactivated aryl substrates often requires several steps, which in itself can be a time-consuming and economically inefficient process.

http://aether.cmi.ua.ac.be/artikels/Artikels%20Gitte/Artikels/Reviews/Heck-Type-lautens.pdf

Aryl-aryl bond formation by transition-metal-catalyzed direct arylation.

THE definitions currently used to classify chemical bonds (in terms of bond order, covalency versus ionicity and so forth) are derived from approximate theories1–3 and are often imprecise. Here we outline a first step towards a more rigorous means of classification based on topological analysis of local quantum-mechanical functions related to the Pauli exclusion principle. The local maxima of these functions define 'localization attractors', of which there are only three basic types: bonding, non-bonding and core. Bonding attractors lie between the core attractors (which themselves surround the atomic nuclei) and characterize the shared-electron interactions. The number of bond attractors is related to the bond multiplicity. The spatial organization of localization attractors provides a basis for a well-defined classification of bonds, allowing an absolute characterization of covalency versus ionicity to be obtained from observable properties such as electron densities.

Classification of chemical bonds based on topological analysis of electron localization functions

The development in the field of coordination polymers or metal-organic coordination networks, MOCNs (metal-organic frameworks, MOFs) is assessed in terms of property investigations in the areas of catalysis, chirality, conductivity, luminescence, magnetism, spin-transition (spin-crossover), non-linear optics (NLO) and porosity or zeolitic behavior upon which potential applications could be based.

/pdf/engineering-coordination-polymers-towards-applications-3joywh2v74.pdf

Engineering coordination polymers towards applications

Crystal structure of 8-chloro-2,4,6-triazatricyclo [7.2.1.02,6] dodeca-7,10-diene-3,5-dione

Struktur von Tetraphenylphosphonium[(Brenzkatechin)chlorid]

Crystal structure of diethyl-methyl-ammonium-trifluoracetyl-methylide-hydrate

Kristallstruktur und chemische Bindung. Von A. Weiss und H. Witte. Verlag Chemie, Weinheim 1983. XI, 396 S., geb. DM 98.00. – ISBN 3‐527‐25612‐1

MIMD parallel computers can be a promising alternative in those cases where application software exploits only a small portion of the maximum performance of vector computers. We compare MIMD systems with other parallel architectures and stress transputer networks pointing out the benefits of this concept. Two different software environments are discussed, MultiTool, a modified transputer development system (TDS) and the distributed operating system Helios. Both are used to implement direct SCF programs on a transputer network. Parallel processing is defined according to the farming concept, both on the program and on the subroutine level. In transputer networks with up to 17 nodes, a very good load balance could be achieved, demonstrating the good suitability of the MIMD-concept for SCF calculations.

Hans Georg von Schnering

Papers

Crystal structure of 8-chloro-2,4,6-triazatricyclo [7.2.1.02,6] dodeca-7,10-diene-3,5-dione

Struktur von Tetraphenylphosphonium[(Brenzkatechin)chlorid]

Crystal structure of diethyl-methyl-ammonium-trifluoracetyl-methylide-hydrate

Kristallstruktur und chemische Bindung. Von A. Weiss und H. Witte. Verlag Chemie, Weinheim 1983. XI, 396 S., geb. DM 98.00. – ISBN 3‐527‐25612‐1

Quantum Chemical Calculations on MIMD Type Computers