Potential-derived charges theory

Edit Output File icon xlix effective core potentials 101 electron affinity 142 electron correlation 6, 114,118 electron density 165 electron spin 259 electronic structure theory 3 electrostatic potential-derived charges CHelpG 196... 

Tel. 412-621-2050, fax 412-621-3563, e-mail info gaussian.com Gaussian 92. Ab initio molecular orbital calculations (Hartree-Fock, Direct HF, Moller-Plesset, Cl, Reaction Field Theory, electrostatic potential-derived charges, vibrational frequencies, etc.). Input and output of molecular structures in formats of many other molecular modeling systems. Browse for archival storage of computed results. VAX, Cray, DEC-RISC (Ultrix), Fujitsu (UXP/M), Kubota, IBM RS/6000, Multiflow, Silicon Graphics, Sun, and other versions. Gaussian 90 for Convex, FPS-500, Fujitsu (MSP), IBM (VM, MVS), HP-700, and NEC SX/3 systems. 

The nitrogen atom of NH2(f-Bu) is a nucleophile that preferentially attacks atoms in the 2,4,6-trimethylpyrylium ring that are depleted in electron density. A density functional theory calculation on the parent unsubstituted pyrylium cation provides the Merz-Kollman-Singh electrostatic potential-derived charges (MKS EPDC) " illustrated in Fig. 1. Which atom(s) of the pyrylium ring are preferentially attacked by the amine ... 

Electrostatic interactions in solutions containing charged particles and ions can be described using the Poisson-Boltzmann equation. A charged surface attracts counterions into a double layer of thickness defined by the Debye length, which depends on counterion concentration and solvent dielectric constant. From simplified theories, expressions can be derived for the attractive interaction potential between charged spheres. 

ASC = apparent surface charge BEM = boundary-element method CPHF = coupled perturbed Hartree-Fock C/RF = classical reaction field GBA = generalized Bom approximation FDM = finite-difference method FEM = finite-element method MPE = multipole expansion PD = potential derived SOS = sum over states SPT = scaled particle theory. 

Garcia etal. [41] developed a two-dimensional porous electrode model and accounted for potential and charge distributions in the electrolyte. They employed transport equations derived from dilute solution theory, which is generally not adequate for LIB systems. The stress generation effect is built into the 2D DNS modeling framework with a simplified, sphere-packed electrode microstmcture description. 

The final part is devoted to a survey of molecular properties of special interest to the medicinal chemist. The Theory of Atoms in Molecules by R. F.W. Bader et al., presented in Chapter 7, enables the quantitative use of chemical concepts, for example those of the functional group in organic chemistry or molecular similarity in medicinal chemistry, for prediction and understanding of chemical processes. This contribution also discusses possible applications of the theory to QSAR. Another important property that can be derived by use of QC calculations is the molecular electrostatic potential. J.S. Murray and P. Politzer describe the use of this property for description of noncovalent interactions between ligand and receptor, and the design of new compounds with specific features (Chapter 8). In Chapter 9, H.D. and M. Holtje describe the use of QC methods to parameterize force-field parameters, and applications to a pharmacophore search of enzyme inhibitors. The authors also show the use of QC methods for investigation of charge-transfer complexes. 

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