Journal ArticleDOI
Group theoretical treatment of classical n-time correlation functions
M.W. Evans
- Vol. 128, Iss: 2, pp 413-428
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TLDR
In this paper, the authors investigated the symmetry and time dependence of higher-order n-time correlation functions in isotropic molecular liquids and in molecular liquids subjected to external electric and magnetic fields.Abstract:
The methods of group theoretical statistical mechanics are used to investigate the set of n -time correlation functions in isotropic molecular liquids and in molecular liquids subjected to external electric and magnetic fields. It is found that the group theory corroborates the results of computer simulation where these are available, both for auto- and cross-correlation functions, in the field-off and field-on equilibrium conditions. Many more elements of the time correlation functions are allowed by symmetry in the presence of fields. For the first time, the symmetry and time dependence of higher-order n -time correlation functions are investigated by group theory. This results in a great simplification of the exploratory work of the computer simulator, because the group theory clearly distinguishes between those elements that vanish for all t and those that may exist in the laboratory frame ( X, Y, Z ) and the molecule-fixed frame ( x, y, z ). Group theoretical statistical mechanics reveal clearly that the statistics of a molecular liquid cannot be Gaussian in general, because three-time and higher-order correlation functions exist by symmetry. These should be observable in future computer simulation. Thus we arrive at the important conclusion that group theory applied to the dynamics of molecules in the liquid state invalidates a large number of literature theories of diffusion, including all those based on the Debye concept of “rotational” diffusion. These theories should be modified accordingly.read more
Citations
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Journal ArticleDOI
Symmetry analysis of non-equilibrium time correlation functions
TL;DR: In this article, a symmetry analysis of non-equilibrium time correlation functions is introduced using the principles of group theoretical statistical mechanics and the new fluctuation dissipation theorem of Morriss and D. J. Evans.
Journal ArticleDOI
Applications of group-theoretical statistical mechanics: Interaction of electromagnetic fields with molecular ensembles.
TL;DR: In this paper, the authors apply group-theoretical statistical mechanics (GTSM) techniques to various aspects of the interaction of electromagnetic radiation with molecular ensembles, and derive classical-quantum equivalence relations at each stage.
Journal ArticleDOI
Group theoretical statistical mechanics applied to couette flow
TL;DR: In this article, the effect of couette flow on a range of ensemble averages is evaluated by establishing the symmetry of the strain rate tensor in terms of the irreducible representations of the R h (3) rotation-reflection group in frame ( X, Y, Z ).
Journal ArticleDOI
Chirality of field induced natural and magnetic optical activity
TL;DR: In this article, the symmetry and chirality of field induced natural and magnetic optical activity are investigated with Barron's definition of Chirality and the third principle of group theoretical statistical mechanics.
Journal ArticleDOI
Field applied molecular dynamics (FMD) computer simulation of circular dichroism and optical rotatory dispersion
M.W. Evans,S. Woźnak,G. Wagnière +2 more
TL;DR: In this paper, the authors used field applied molecular dynamics (FMD) computer simulation to investigate circular dichroism (CD) and optical rotatory dispersion (ORD) in the picosecond time window (far infrared frequency interval) using second order rise transients (RSs) and a range of time correlation function (CFs).
References
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Journal ArticleDOI
Molecular dynamics simulation of water from 10 to 1273 K
TL;DR: In this paper, the molecular dynamics of liquid water have been simulated over a wide range of thermodynamic conditions using a five by five site-site model for the intermolecular potential recently developed by Evans.
Journal ArticleDOI
Molecular-dynamics simulation of liquid water with an ab initio flexible water-water interaction potential. II. The effect of internal vibrations on the time correlation functions.
Journal ArticleDOI
Molecular dynamics of liquid water in a circularly polarized external field
TL;DR: In this paper, the dipole moment of a water molecule was subjected to an external circularly polarized field of force and the effect on the molecular dynamics evaluated through novel laboratory and moving frame cross correlation functions (ccf) using molecular dynamics computer simulation.
Journal ArticleDOI
Inertial effects in the theory of dielectric and Kerr effect relaxation of an assembly of non-interacting polar molecules in strong alternating fields
TL;DR: In this paper, the ensemble averages of the Fokker-planck equation and the Smoluchowski equation were calculated for alternating fields, where the polar molecules can rotate in space.
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