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Adiabatic approach switching

In this section, we switch gears slightly to address another contemporary topic, solvation dynamics coupled into the ESPT reaction. One relevant, important issue of current interest is the ESPT coupled excited-state charge transfer (ESCT) reaction. Seminal theoretical approaches applied by Hynes and coworkers revealed the key features, with descriptions of dynamics and electronic structures of non-adiabatic [119, 120] and adiabatic [121-123] proton transfer reactions. The most recent theoretical advancement has incorporated both solvent reorganization and proton tunneling and made the framework similar to electron transfer reaction, [119-126] such that the proton transfer rate kpt can be categorized into two regimes (a) For nonadiabatic limit [120] ... [Pg.248]

Closely related to TI is the adiabatic switching method of Watanabe and Reinhardt [49]. This approach involves following a thermodynamic path via a molecular dynamics simulation in which the parameter A. varies slowly with time. For a sufficiently slow variation, the process is adiabatic and the entropy of the initial and final states will be the same extensions of the basic idea permit evaluation of isothermal and other free-energy changes. The question of how slow the variation must be to remain an adiabatic process has been the subject of some study and analysis [50,51]. De Koning and Antonelli [52] have demonstrated its use by calculating the difference in free energy between two Einstein crystals. [Pg.125]

The adiabatic switching semiclassical quantization method [60-62] may also be used to choose initial conditions for polyatomic reactants. This approach does not require an explicit determination of the topologically independent paths Ct and actions Jt for Eq. (3.36) and, in principle, may be more easily applied to larger polyatomics than the EBK semiclassical quantization approach described above. However, what is required is a separable zero-order Hamiltonian H0 that gives rise to the same kind of intramolecular motion as does the complete Hamiltonian [63,64]. [Pg.194]

In this section we describe several methods not pertaining to the techniques described earlier. We discuss the multicanonical method of Berg as applied to macromolecules, " " - and the adiabatic switching procedure of Rein-hardt, which is related to the thermodynamic integration approach but is based on different grounds. For completeness, we mention four additional techniques, three of which were developed originally for spin models. [Pg.55]

Quantum Adiabatic Switching and Supersymmetric Approach to Excited States of Nonlinear Oscillators... [Pg.43]

Chou, C.-C., T. Markovich, and D. J. Kouri. 2012. Adiabatic switching approach to multidimensional supersymmetric quantum mechanics for several excited states. Molecular... [Pg.62]

Lower limit of the evolution field When the evolution field approaches the earth field, i.e. the field when the magnet is switched off, a compensation of this zero-field with the aid of correction coils becomes necessary. In this way, flux densities less than 5 X 10 T can reliably be reached. Another limit is due to the local field within the sample. The local field arises because of secular spin interactions. It can therefore not be compensated by external correction coils. If the local field exceeds the external evolution field, two situations can arise. Firstly, the local field is approached by adiabatically switching off the polarization field. That is, the local magnetization vectors follow the instantaneous field direction which is finally given by the local field. In this case, dipolar or, in the case of quadrupole nuclei, quadru-polar order is produced. The relaxation time measured under such circumstances is the dipolar-order spin-lattice relaxation time. In the opposite case, the... [Pg.839]


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See also in sourсe #XX -- [ Pg.44 ]




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