Molecule geometry

Ab initio calculations, correlations of molecules geometries, spectroscopic data with chemical properties, and quanta-tive structure-activity relationship have been conducted for both furazans and furoxans. Thus, the structures of 1,2,5-oxadiazole (furazan) and benzo[c][l,2,5]oxadiazole (benzofurazan) have been calculated by ab initio and Becke3-LYP... 

The other effect operates not through bonds but directly through space or solvent molecules and is called the field effect. Generally, the field effect depends on the molecule geometry, but the inductive effect depends only on the nature of the bonds. In most cases, the two types of effects are considered together more recently, evidence suggests that field effects are a more important mode of transmission than resonance effects (Hansch and... 

The advantages come from geometric simplicity the orientation of the molecules with respect to the solute does not have to be optimized, nor does the more ambitious task of solute molecule geometry optimization arise. 

As an appropriate illustration of possible errors in situations like in the example discussed here, the apparent dependence of molecular geometry upon temperature is given in Fig. 11.7a and b. Although there is not, seemingly, any systematic trend in the observed values as a function of temperature, in some fragments of the molecule, geometry variation with temperature is very impressive. However, all these are apparent [6],... 

Table 2 Bond lengths (pm) for selected molecules, as calculated with various functionals. Summary of results (deviations from experimental values) obtained for a subset of the G2 set of molecules. Geometries determined either through standard optimizations (opt) or PES scans (scan).

Recent experiments (36, 37) using the mass spectrometer have provided values for the electronic properties of (CuCl) clusters. The CNDO procedure has been applied to these clusters by Baetzold and Mack (unpublished data) to determine whether trends in a series of similar dusters would be reproduced. Input parameters were chosen by fit to experimental data for Cu2 and Cl2 molecules. Geometries are predicted with general accuracy although fine detail may be missed. For example, a regular hexagon is predicted as the low-energy... 

Geometries are those optimized by STO-3G for the parent molecules. Geometries are fully optimized for the substituted compounds by MINDO/3. Only the geometrical parameters listed are optimized by STO-3G. 

Methane, bromination mechanism, 60 Methide shift, 94 Methylene in synthesis, 67 Methyl salicylate, 440 Michael addition, 385, 459 Microscopic reversibility, 98 Migratory aptitude, 293 Molecular orbital, 14 Molecularity, 40 Molecules, geometry of, 18 polar, 27... 

To clarify the mechanism of propylene adsorption on Ru-Co clusters the quantum-chemical calculation of interaction between it and Ru-Co, Ru-Ru, and Co-Co clusters were carried out. During the calculation it was assumed that carbon atoms of C-C bond are situated parallel to metal-metal bond. The distance at which the cluster and absorbable molecule begin to interact is characterized by the nature of active center. Full optimization of C3H6 molecule geometry confirms that propylene adsorbs associatively on Co-Co cluster and forms Jt-type complex. In other cases the dissociate adsorption of propylene is occurred. The presence of Ru atom provides significant electron density transfer from olefin molecule orbitals to d-orbitals of ruthenium in bimetallic Ru-Co- or monometallic Ru-Ru-clasters (independently on either the tertiary carbon atom is located on ruthenium or cobalt atom.). At the same time the olefin C-C bond loosens substantially down to their break. 

Molecule geometry (they are present as regular helices and p-sheets or as irregular packed coils of varying density). 

Since the electron interactions in the overlap regions are omitted, the predicted binding energies are not precise, and we need to compare the surface or molecule geometries. By considering... 

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