Peaks pair distribution function

Figure 5. The Fourier transformed signal AS[r, i] of I2/CCI4. The pump-probe delay times are I = 200 ps, 1 ns, and 1 ps. The green bars indicate the bond lengths of iodine in the X and A/A states. The blue bars show the positions of the first two intermolecular peaks in the pair distribution function gci-ci- (See color insert.)...

Figure 6. The Fourier transformed signal AS[r, i] of CH2I2/CH3OH. The pump-probe time delays vary between i = —250 ps and 1 ps. The pair distribution function gl-I peaks in the 3 A region. If T < 50 ns, the I—I bond corresponds to the short-lived intermediate (CH2ri), and if x > 100 ns it belongs to the (I3") ion. Red curves indicate the theory, and black curves describe the experiment.

The value of the peaks and troughs in the pair distribution function represent the fluctuation in number density. The peaks represent regions where the concentrations are in excess of the average value while the troughs represent a deficit. As the volume fraction is increased, the peaks and troughs grow, reflecting the increase in order with concentration. We... 

The exciplex is formed with a particle that enters the first coordination sphere of the excited partner. This sphere is distinctive from others even in pure liquids where it is marked by the strongest peak in the pair distribution function. In this case k are simply the rates of jumps in and out of the nearest shell. They are... 

A second piece of indirect evidence relating the 30 ppm peak in aluminosilicates to Al rather than Al species comes from large angle X-ray scattering (LAXS) experiments on aluminosilicate glasses (Schmiicker et al. 1999). The aluminium site occupancies of a number of glass compositions were determined from their Al NMR spectra and used to calculate the pair distribution function (PDF) profile which was... 

The pair distribution function, g(r), gives the probability of finding an atom (or molecule, if simulating a molecular fluid) a distance r from another atom (or molecule) compared to the ideal gas distribution. g(r) is thus dimensionless. Higher radial distribution functions (e.g. the triplet radial distribution function) can also be defined but are rarely calculated and so references to the radial distribution function are usually taken to mean the pairwise version. In a crystal, the radial distribution function has an infinite number of sharp peaks whose separations and heights are characteristic of the lattice structure. 

The OPs developed by Santiso and Trout [65] are extracted from a generalized pair distribution function. All OPs used in this stody were based on [dmim ] no particular OPs were defined for [Cl ]. In Fig. 1 two ion pairs are shown, where the absolute orientation of each cation is given by the vectors qi and q2, which are normal to the imidazolium ring of each cation. The distance OP provides quantification for the various center of mass (COM) distances between the cations. The bond orientation OP measures the orientation of bonds joining the center-of-mass of the cations, while the relative orientation OP measures the orientation of one cation with respect to another one [65,67]. All the OPs are defined per cation and per peak... 

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