Energy transfer Probability

Hold U, Lenzer T, Luther K, Reihs K and Symonds A C 2000 Collisional energy transfer probabilities of highly excited molecules from kinetically controlled selective ionization (KCSI). I. The KCSI technique experimental approach for the determination of P(E, E) in the quasicontinuous energy ranged. Chem. Phys. 112 4076-89... 

C3.3.5.2 EXTRACTING THE ENERGY TRANSFER PROBABILITY DISTRIBUTION FUNCTION P(E, E)... 

Figure C3.3.11. The energy transfer probability distribution function P(E, E ) (see figure C3.3.2) for two molecules, pyrazine and hexafluorobenzene, excited at 248 nm, arising from collisions with carbon dioxide...

Figure C3.3.12. The energy-transfer-probability-distribution function P(E, E ) (see figure C3.3.2 and figure C3.3.11) for two molecules, pyrazine and hexafluorobenzene, excited at 248 nm, arising from collisions with carbon dioxide molecules. Both collisions that leave the carbon dioxide bath molecule in its ground vibrationless state, OO O, and those that excite the 00 1 vibrational state (2349 cm ), have been included in computing this probability. The spikes in the distribution arise from excitation of the carbon dioxide bath 00 1 vibrational mode.

The use of supercomputers has allowed us to test the sensitivity of accurate quantal molecular energy transfer probabilities in diatom-diatom collisions to the choice of potential energy surface, even at total energies great enough to allow both diatoms to be vibrationally excited. 

Energy transfer probabilities due to multipolar magnetic interactions also behave in a similar way to that previously discussed for multipolar electric interactions. Thus, the transfer probability for a magnetic dipole-dipole interaction also varies with 1 / 7 , and higher order magnetic interactions are only influential at short distances. In any case, the multipolar magnetic interactions are always much less important than the electric ones. 

Influence of Charge-transfer and 4/ i5d States on Energy Transfer Probabilities 68... 

Table 8. Energy transfer probabilities for associates VO Ln studied in YVO4, CaS04 and PbS04 ( — no transfer, 4- efficient transfer, 0 transfer probability low to medium)...

INTERMOEECUEAR ENERGY TRANSFER PROBABILITY DENSITY FUNCTION... 

One of the most important and elusive quantities in molecular djmamics calculations of reacting system is the intermolecular energy transfer probability density function P(E ,E) which is used in master equation calculations of reaction rate coefficients [1]. 

Trajectory calculations together with ab initio inter and intramolecular potential are efficient and productive in producing detailed information on the mechanism of binary and termoleeular collisions and provide numerical values of collisional energy transfer quantities such as the average energy transferred in a collision, the average lifetime of binary and temaiy collision complex, the energy transfer probability density function, supercollisions and the second virial coefficient. 

Oref, I. and Bemshtein. V. (1998) Intermolecular energy transfer probabilities from trajectory calculations - A new approach, J. Chem. Phys., 108, 3543. 

As mentioned above, the slow component of the excitation energy transfer to [Cr(bpy)3]3+ is due to [Cr(ox)3]3- complexes, which do not have an acceptor in the nearest neighbour shell, but do have acceptors in further shells. In this case superexchange can be ruled out as interaction mechanism because there is no reasonable pathway for an overlap of the relevant electronic wave functions. The most probable interaction is electric dipole-di-pole interaction, for which the energy transfer probability according to Eq. (1) in SI units takes the form [10]... 

The energy transfer probability from U02+ to various rare earth ions in phosphate glasses is presented in Fig. 5. It can be seen from the figure that Pr3+ ions present an interesting case for LSC. 

Using Eq. (13), Watts (10) plotted the energy transfer probabilities versus interionic separation for ytterbium-erbium transfer rate d-d (a(6)), d-q (a(8)) and q-q (a(10)). From his data it may be seen that the quadrupole-quadrupole mechanism is the highest and dipole-dipole lowest at small interionic distances and become of the same order of magnitude at around 8 A. At higher distances the situation is inverted, for example, at around 10 A the dipole-dipole is highest and quadrupole-quadrupole lowest. 

In this paper we have made an attempt to show how energy transfer probabilities can be calculated for various mechanisms in the microscopic and macroscopic cases and the optical methods used so far by which the macroscopic energy transfer can be obtained experimentally. It has been shown that the resonance transfer plays only a minor role and additional mechanisms such as phonon-assisted energy transfer and diffusion of energy within the donor systems must be considered. 

Other quenchers that have been used in the benzophenone-sensitized cis trans isomerization of stilbene are /9-carotene, oxygen, and di-tert-butyl nitroxide. /9-Carotene shifts the photostationary state to the trans side similar to the azulene effect [237]. In the presence of di-tert-butyl nitroxide, a radical quencher, the photostationary state is slightly shifted to the cis side Caldwell and Schwerzel [226] have suggested the involvement of the twisted triplet state and a quenching mechanism other than energy transfer, probably vibrational relaxation to the ground state caused by spin exchange. 

D. W. Schwenke, S. L. Mielke, G. J. Tawa, R. S. Friedman, P. Halvick and D. G. Truhlar, Converged quantum mechanical calculations of electronic-to-vibrational, rotational energy transfer probabilities in a system with a conical intersection, J. Chem. Phys. 203 565 (1993). 

A representation of the cascading process is shown in Figure 2 for the hypothetical stepladder situation in which only constant AE increments are allowed. More complex transition probabihty models utilize statistical descriptions of the energy transfer probability density [P(AE)]. For such cases individual collisions probe a range of AE values, but the average energy transfer increment ( ) remains constant. 

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