Calculation of structural

Crain J, Clark SJ (1999) Calculation of Structure and Dynamical Properties of Liquid Crystal. 94 1-39... 

Calculation of Structure and Dynamical Properties of Liquid Crystal Molecules... 

Although experimental studies provide significant amounts of information regarding the structure and the catalytic activity of these enzymes, several issues concerning the structure (presence of water in the active site) and the catalytic mechanism remained unresolved. Based on the complete X-ray structure of human plasma GPx (2.9 A resolution) [64], we performed active-site and ONIOM QM MM calculations of structure and reaction mechanism [27, 28, 65],... 

AMI semi-empirical calculations of structures 23-25 have been carried out to provide a rationale for the obtained nuclear magnetic resonance (NMR) results (Section 12.10.3.3.1). According to the calculations, compound 25 is planar with E conformation having the =C(CN)2 group directed toward the H-2 <1997MI113>. 

It should be kept in mind that quantum chemical calculations of structures and magnetic properties generally are done for the isolated carbocation without taking into account its environment and media effects such as solvent, site-specific solvation or counterion effects. This is a critical question since NMR spectra of carbocations with a few exceptions are studied in superacid solutions and properties calculated for the gas-phase species are of little relevance if the electronic structure of carbocations is strongly perturbed by solvent effects. Provided that appropriate methods are used,... 

R. Chelli, F. F. Gervasio, C. Gellini, R Procacci, G. Cardini, and V. Schettino, Density functional calculation of structural and vibrational properties of glycerol. J. Phys. Chem. A 104, 5351 5357 (2000). 

A speculative proposal was made thirty years ago by Schmid and Krenmayr77, namely that a nitrosyl ion solvated, but not covalently bonded, by a water molecule may be involved in these systems. This hypothesis was investigated theoretically in 1984 by Nguyen and Hegarty78 who carried out ab initio SCF calculations of structure and properties employing the minimal STO-3G basis set, a split-valence basis set plus polarization functions. Optimized geometries of six planar and two nonplanar forms were studied for the nitrosoacidium ion. The lowest minimum of molecular electrostatic potential... 

Due to the superior performance of the H-73 basis set in the Cl calculations of structures and energies for the excited states of hydrogen molecule, it was used in the subsequent studies of H2 enclosed in a cylindrical harmonic potential. The PECs of the ground and eight low-lying excited states of H2 encapsulated... 

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