Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 3933-3937 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Monte Carlo calculations have been carried out to study the interfacial properties of liquid water, using the Matsuoka–Clementi–Yoshimine (MCY) potential for the water–water interaction. The surface tension calculated at 298 K is 23.7±3.4 dyn/cm, to be compared with the experimental value of 72 dyn/cm. The interfacial 10–90 thickness is 4.70 A(ring), with the dipoles of the water molecules near the liquid phase pointing slightly towards the liquid phase and those near the gas phase pointing towards the gas phase. The interfacial water molecules are found to be more restricted in their rotation, as evidenced by the smaller root-mean-squared fluctuations of the dipole directions. The Volta potential difference across the interface arising from the permanent dipoles is estimated to be 0.024 V. A new and efficient method is proposed to calculated the surface excess energy. The excess energy calculated for the MCY water is 119 erg/cm2, to be compared with the experimental value of 120 erg/cm2. From the calculated surface excess energy, the temperature variation of the surface tension, or the surface entropy, for the MCY water is estimated to be −0.32 dyn/(cm2 K). This temperature variation is confirmed by another Monte Carlo study at 310 K to within the calculated uncertainty.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 6985-6998 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The Smoluchowski–Collins–Kimball theory of irreversible diffusion-influenced reactions with one of the reactants in excess is generalized to the case of stochastic gating when one of the reactants can be in one of M states. Distinct states are characterized by various efficiencies of the reaction of contacting partners. General expressions are derived for the rate constant and for the survival probability of the reactant which is in deficiency. We present these quantities in terms of the solution of the isolated pair problem. The difference between the cases when gating is due to the reactant, which is in excess, and one, which is in deficiency, is explicitly demonstrated. General relationships between the rate constants and the survival probabilities in the two cases are established. We show that in the former case the reaction goes faster compared to the latter one. To make the problem treatable analytically in the case when gating is due to the reactant which is in deficiency, a partial mean-field approximation is introduced. General theory is applied to a particular case of the two-state gating model. Explicit analytical solutions for the time-dependent rate constant and the survival probability are obtained in one dimension. They illustrate the general theory as well as show how the kinetics depends on the jump rate between the two states of the gate in both cases when gating is due to the reactant, which is in excess, and one, which is in deficiency. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 9361-9369 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We study the tunneling behavior in a curve crossed parabolic free energy surface with friction via a dwell time method. The dwell time is defined as the difference of the mean first passage time between the delocalized and the localized nonadiabatic electron transfer reactions. The equation of motion of nonadiabatic electron transfer reaction in the condensed phase obeys a semiclassical Zusman equation [L. D. Zusman, Chem. Phys. 40, 295 (1980)]. By using the eigenfunction expansion method, the dwell time and the tunneling probability density at short time are solved numerically. It is shown that the dwell time of the nonadiabatic electron transfer reaction between two parabolic free energy surfaces depends on the delocalization width (or diabatic width) and the force difference at the crossing point. This dwell time is proportional to (longitudinal dielectric relaxation time)/(electronic coupling constant)2. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 9427-9438 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A theory of pump–probe spectroscopy of photoinduced charge separation processes in solution is developed. The pump–probe pathway is described by pump with excitation pulse which generates a nonstationary initial state in the first excited state. This initial state evolves and transfers to a second excited state (charge transfer state) nonadiabatically, and the system is probed by a second probe pulse. Doorway and window function approximations are used to separate these processes. Solution is treated as a continuum (Debye) model with one longitudinal relaxation time. Hence, after Wigner transformation of the time evolution of density matrix in Liouville space, the solvation dynamics of nonadiabatic charge separation processes obeys the semiclassical Zusman equation. Using the eigenfunction expansion method, we solve the bare absorption spectrum numerically. An electronic coherence motion is observed in the overdamped exothermic invert regime. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 74 (1994), S. 631-661 
    ISSN: 1572-9613
    Keywords: Electron transfer theory ; projector formalism ; Fokker-Planck equation ; Zusman equation ; generalized moment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We discuss the generalized moments of the nonadiabatic transition reaction by using the stochastic Liouville equation for the study of outer-sphere electron transfer in polar solvents characterized by Debye dielectric relaxation. We obtain an approximate expression for the generalized moments which incorporates the width of the transition with arbitrary initial condition far from equilibrium. For low barriers, we derive an analytical expression for the rate corresponding to harmonic potential surfaces in the overdamped regime. For Fokker-Planck operators of Smoluchowski type, we introduce a new method to solve all of the generalized moments by using the eigenfunction expansion method.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...