Configuration coordinate

Fig. 9. Two-dimensional sketch of the 3N-dimensional configuration space of a protein. Shown are two Cartesian coordinates, xi and X2, as well as two conformational coordinates (ci and C2), which have been derived by principle component analysis of an ensemble ( cloud of dots) generated by a conventional MD simulation, which approximates the configurational space density p in this region of configurational space. The width of the two Gaussians describe the size of the fluctuations along the configurational coordinates and are given by the eigenvalues Ai.

The Configuration Coordinate Model. To illustrate how the luminescent center in a phosphor works, a configurational coordinate diagram is used (2) in which the potential energy of the luminescent or activator center is plotted on the vertical axis and the value of a single parameter describing an effective displacement of the ions surrounding the activator, is plotted on the horizontal axis (Fig. 2). At low temperatures, near room... 

Fig. 2. General configurational—coordinate diagrams for (a) broad-band absorbers and emitters, and (b) narrow-band or line emitters. The ordinate represents the total energy of the activator center and the abscissa is a generalized coordinate representing the configuration of ions surrounding the...

Fig. 3. A configurational—coordinate diagram showing mechanisms of radiationless decay to the ground state. Nonradiative decay to the ground-state...

Oxidation state Electronic configuration Coordination number Metal atom geometry Example CAS Registry Number... 

Figure 7-12. Configuration coordinate diagram of the four essential states showing the photophysical processes. Also shown is the calculated PA spectrum based on level energies from EA spectroscopy.

Fig. 12. Configurational coordinate diagram of Prussian blue. Curve g gives the ground state Fe(III)-NC-Fe(II) Curve e gives the MMCT state Fe(II)-NC-Fe(III). The optical transition is indicated by E p, whereas Eo gives the energy difference between the two states. See also text (after data in Ref. [66])...

There is no essential difference between quenching via a MMCT state or a LMCT state. The latter occurs, for example, in Eu(III) if the LMCT state is either at low energy or if this state shows a large offset in the configurational coordinate diagram [23, 35]. The latter occurs in glasses [123], certain cryptates [124] and lanthanum compounds [125]. 

If we describe the state of the medium molecules by one effective configurational coordinate q, the free energy surfaces of the solvent Uim and Ufn have the form55... 

In most applications of transition path sampling it is sufficient to define the stable regions si and 88 in terms of configurational coordinates without reference to the momenta. The transition path sampling formalism, however, can be also applied to situations in which si and 88 also depend on the atomic momenta. 

Keywords Spin crossover Ligand field theory Optical properties Vibronic structure Configurational coordinate... 

Figure 56 Configuration coordinate model for higher-dimensionality polysilanes.360 Reprinted with permission from Watanabe, A. J. Organomet. Chem. 2003, 685, 122-133, 2003 Elsevier.

The dynamics of polysilane dendrimer excited states were also studied by Watanabe as mentioned above in a comparison with polysilynes,360,364 and suggested that a configuration coordinate model is applicable to the photophysics of branched silicon chains. Calculations showed a distorted geometry of the excited state localized at a branching point. 

Two configurational coordinate models, presented in Figure 11.13 and 11.14, are sufficient to allow the interpretation of the temperature dependences of the Cr3+ fluorescence in crystal materials qualitatively, even quantitatively to an extent of sufficient precision for thermometric applications, as shown in the cases of CnLiSAF, alexandrite, and ruby. In high-field-strength host crystals, two mechanisms, the thermal repopulation of the 473 and 2E states and the nonradiative process, dominate the... 

Figure 11.13. The single configurational coordinate model for Cr5 fluorescence in low-field crystals, r = configurational coordinate.

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