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Submitted on 1 Jan 1985
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DYNAMICS OF THE ANISOTROPIC STRUCTURE
OF FLUIDS
S. Hess
To cite this version:
JOURNAL DE PHYSIQUE
Colloque C9, supplément au n012, Tome 46, décembre 1985 page C9-91
D Y N A M I C S OF T H E A N I S O T R O P I C STRUCTURE O F F L U I D S
S . Hess
I n s t i t u t fi& Theoretische Physik, TU Berlin, F.R.G.
The positional arrangement of atoms surrounding a specific refer- ence particle at a given instant is anisotropic even in isotropic fluids; the overall isotropy as apparent in the equilibrium pair correlation function results £rom temporal and spatial averages. From theoretical considerations, one may expect that the dynamics of the local anisotropy
-
in particular for the case where it has the same symmetry as the crystalline phase-
is slowed down when a liquid approaches the freezing transition or when it is in a supercooled state /1-3/. In thermal equilibrium, information on the local aniso- tropy is accessible only via 3- and 4-particle correlation functions or through fluctuations of the pair-density /4/. In nonequilibrium molecular dynamics, on the other hand, it is possible to prepare asystem in an initial state with preferential bond-orientational order and to observe the dynamics of the local structure via the approach of the anisotropic pair-correlation function to its isotropic equilib- rium state as well as through the decay of bond-orientational order parameters /5,6/.
1 S. Hess, 2. Naturforsch.
35a
(1980) 692 A.C. Mitus and A.Z. Patashinskii, Phys. Lett.
87A
(1982) 1793 D.R. Nelson and J. Toner, Phys. Rev. (1981) 363
4 N.A. Clark, B.J. Ackerson, and A.J. Hurd, Phys. Rev. Lett. (1983) 1459 5 S. Hess, Physica (1984) 509
6 S. Hess, J. de Physique, Suppl.
