Density functional theory characterized

L.A. O Dell, C.I. Ratcliffe, X. Kong, G. Wu, Multinuclear solid-state nuclear magnetic resonance and density functional theory characterization of interaction tensors in taurine,. Phys. Chem. A 116 (2012) 1008. 

Deskins NA, Dupuis M (2007) Electron transport via polaron hopping in bulk Ti02 a density functional theory characterization. Phys Rev B 75(19) 195212... 

C. Lo and B. L. Tront. Density-functional theory characterization of acid sites in chaba-zite. J. Catal. 227, 2004, 77-89. 

S. Chains in the S phase are also oriented normal to the surface, yet the unit cell is rectangular possibly because of restricted rotation. This structure is characterized as the smectic E or herringbone phase. Schofield and Rice [204] applied a lattice density functional theory to describe the second-order rotator (LS)-heiTingbone (S) phase transition. 

The resulting similarity measures are overlap-like Sa b = J Pxi ) / B(r) Coulomblike, etc. The Carbo similarity coefficient is obtained after geometric-mean normalization Sa,b/ /Sa,a Sb,b (cosine), while the Hodgkin-Richards similarity coefficient uses arithmetic-mean normalization Sa,b/0-5 (Saa+ b b) (Dice). The Cioslowski [18] similarity measure NOEL - Number of Overlapping Electrons (Eq. (10)) - uses reduced first-order density matrices (one-matrices) rather than density functions to characterize A and B. No normalization is necessary, since NOEL has a direct interpretation, at the Hartree-Fodt level of theory. 

Fischer-type carbene complexes, generally characterized by the formula (CO)5M=C(X)R (M=Cr, Mo, W X=7r-donor substitutent, R=alkyl, aryl or unsaturated alkenyl and alkynyl), have been known now for about 40 years. They have been widely used in synthetic reactions [37,51-58] and show a very good reactivity especially in cycloaddition reactions [59-64]. As described above, Fischer-type carbene complexes are characterized by a formal metal-carbon double bond to a low-valent transition metal which is usually stabilized by 7r-acceptor substituents such as CO, PPh3 or Cp. The electronic structure of the metal-carbene bond is of great interest because it determines the reactivity of the complex [65-68]. Several theoretical studies have addressed this problem by means of semiempirical [69-73], Hartree-Fock (HF) [74-79] and post-HF [80-83] calculations and lately also by density functional theory (DFT) calculations [67, 84-94]. Often these studies also compared Fischer-type and... 

A group of investigators recently suggested that the density-functional theory (DFT), which calculates IR and Raman spectra, is a useful tool for direct characterization of the structures of diamondoids with increasing complexity [66]. They applied DFT to calculate Raman spectra whose frequencies and relative intensities were shown to be in excellent agreement with the experimental Raman spectra for C26H30, thus providing direct vibrational proof of its existence. 

Fig. 3 Ir4 cluster supported at the six-ring of zeolite NaX as represented by density functional theory samples were characterized by Extended X-ray absorption fine structure (EXAFS) spectroscopy and other techniques [32]...

Fig. 4 Osmium clusters supported on MgO(OOl) a OssC/MgisOs and b OS5C at a surface point Vs defect site [33] these were represented by density functional theory, and the samples were characterized by EXAFS spectroscopy, transmission electron microscopy, and other techniques [15]...

Much remains to be done to develop the chemistry of organic hgands on supported metal clusters, and substantial progress is to be expected as the samples are well suited to characterization, by IR, NMR, and neutron scattering (F. Li, J. Eckert, and B.C. Gates, unpubhshed results) spectroscopies, as well as density functional theory. 

The W-acyliminium ion can be characterized by FTIR spectroscopy as well.9 The starting carbamate 1 exhibited an absorption at 1694 cm 1 due to the carbonyl stretching, while the V-acyliminium ion 2 generated by the cation pool method exhibited an absorption at 1814 cm 1. The higher wave number observed for the cation is consistent with the existence of a positive charge at the nitrogen atom adjacent to the carbonyl carbon. The shift to higher wave number is also supported by DFT (density functional theory) calculations. 

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