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Car-Parinello molecular dynamics (CPMD) simulations of the liquid imidazolium chloride/Al[Cl.sub.3] by inserting one pair of [[C.sub.2][C.sub.1]im] into liquid Al[Cl.sub.3] forming an acidic mixture is described. Large anions within the equilibrium phase are found for both simulations and these large anion species are formed to account for the lack of electrons present in the acidic melt.

A vibrational analysis of 2-fold hydrogen bonds between an isophthalic amide donor and different acceptors is described. The results have indicated that the pronounced blue shift of the C-H stretch mode is basically caused by the fact that the acceptor is fixed directly above this group due to the 2-fold hydrogen bond.

The idea of detecting a hydrogen bond solely on one single quantum chemically determined descriptor is extended. It is demonstrated that a classification according to acceptor atoms of the hydrogen-bonded complexes can give more accurate results.

Chiral, enantiopure metallo-supramolecular rhombs self-assemble in solution through coordination of bis-pyridyl-substituted ligands with (en)M(NO3)2. Characterization by nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopy in solution and by electospray ionization Fourier transform ion cyclotron resonance (ESI-FT-ICR) mass spectrometry in the gas phase suggests that an equilibrium exists in water/methanol of a major 2:2 complex and a minor 3:3 complex of ligands and metal corners.

Vertical and adiabatic excitations of the s-tetrazine molecule, small clusters with water molecules and a single s-tetrazine molecule within 60 water molecules using periodic boundary conditions is studied. They achieved a consistent description of s-tetrazine from the isolated molecule to full solvation in water.

The way in which the standard population analysis can be utilized for a semiquantitative analysis of intermolecular interactions is presented. The report stated that the ability to extract additional information on the system from its electronic structure was offered by increasing availability of wave functions for large many-atom systems in molecular dynamics simulations-either in CPMD simulations or in single-point calculations on MD snapshots.

The deuteron quadrupole coupling constant of water together with dimethyl sulfoxide was studied using computer simulations.

A theoretical study of amide pseudorotaxane IR spectra in the harmonic approximation is carried out to examine the effect of axle substitution on the hydrogen bonds that are formed between axle and wheel. A clear relation observed between the NH stretch shifts and individual hydrogen bond energies is confirmed by correlations of the shared electron number with the NH stretch shift which is an indicator for individual hydrogen bond energies.

Molecular dynamics simulations with an all-atom model are used for studying the structural and dynamics properties of ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim][P[F.sub.6]]). The studies have reproduced the phenomenon where electrical conductivity of ionic liquids has deviated from the Nernst-Einstein relation and it is shown to result from the correlated motion of cations and anions over time scales up to nanoseconds.

The density functional theory methods were used to study mechanistic details of catalytic dinitrogen reduction mediated by Schrok's molybdenum complex under ambient conditions. The results demonstrated that the [[Mo](NN[H.sub.3]).sup.+] complex easily loses ammonia even in the absence of a reductant.

The first-principles molecular dynamics simulations of the alanine hydration was carried out to test the validity of the cluster ansatz approach and the continuum model approach. Sufficient convergence of the cluster ansatz approach is observed for either of the two solvent shells around the polar groups and one solvent shell around the apolar groups or two solvent shells around the polar groups surrounded by a dielectric continuum.

[Hbet][Tf2N] is a versatile task-specific ionic liquid that could be used for the selective solubilization of metal oxides and metal salts. The concept of solubilizing metal oxides in a task-specific ionic liquid is based on the presence of acidic functional groups in the ionic liquid.

The properties of isolated AlCl3 clusters and the bulk system were investigated by means of static and dynamic electronic structure calculations and Car-Parrinello simulations. Important structure motifs with the edge connectivity dominant in a dimer and the corner connectivity dominant in a trimer were found and dimers were the most abundant species but trimers, tetramers, and pentamers were also present and a small percentage of corner connectivity was present that might be attributed to the most stable corner-connected cluster, the trimer.

Density functional theory (DFT) was conducted for examining the thermodynamic boundary conditions for dinitrogen reduction under mild and ambient conditions. The 80.6 kJ/mol is required for the dissociation of NH3 from the cationic complex [Mo]NNH3(super +).

A biomimetic complex, which mimics the arginine phosphonate diester interaction of the arginine fork, is investigated with respect to structure and energetics of stable configurations. Different tweezer guest structures are evaluated with respect to their temperature-dependent thermodynamical properties as products of the first association reaction step of the bisphosphonate tweezer template and the guanidinium moiety.

Aromaticity and homoaromaticity of a parent barbaralane and a tetraphosphabarbaralane of C2-symmetry are visualized by means of three-dimensional nucleus-independent chemical shift (NICS) maps. The characteristic response properties of the electronic structure of these molecules are highlighted.

An approach is presented that allows NMR relaxation rates to be determined for a complex mixture, and it is applied to a dimethyl sulfoxide/water solution. The calculation of the spin-lattice relaxation times (T1) and relaxation rates (R1 = (T1)(super -1) is discussed.

Time-independent quantum chemical methods is employed to examine possible clusters for the stable supermolecules at mole fraction n(sub DMSO)= 0.25 and 0.33 in DMSO-water mixtures. Structure and interaction energetics indicated that the methyl-water interactions become more important upon solvation.