157.
Summary In the present review of liquid dynamics studies on liquid metals are reported. Particularly the case of liquid lead is reviewed
because this case was carefully studied by neutron scattering technique,
S(
Q,ω) being determined at two widely different temperatures
T=623 K and
T=1170 K and therefore different densities. In addition extensive supplementary MD simulations were made using a 16 384-particle
system. The simulations ranged from a determination of an effective pair potential for lead to simulation of the density correlation
functions
F(
Q,
t) and
F
s(
Q,
t), as well as the longitudinal and transversal current correlation functions
J
1(
Q,
t) and
J
T(
Q,
t). The MD simulation ?calibrated? via the experimental
S(
Q) and
S(
Q,ω) was used to prolong the range of neutron data to draw conclusions regarding such quantities as dispersion relations for
the current correlations
J
1(
Q,
t) and
J
T(
Q,
t), the generalized viscosity functions ν
1(
Q,
t), ν
1(
Q) and ν
s(
Q). Information regarding bulk viscosity ν
B(
Q) is also gained. Conclusions are drawn regarding the relative importance of the derived pair potential form by comparison
to corresponding hard-sphere data. The general framework of linearized hydrodynamic equations for the macroscopic situation
transforming to visco-elastic equations of motion for finite wave-length and high frequency works well also for the case of
a continuous potential. The region of transition from simple visco-elastic to hydrodynamic behaviour is occurring at wavelengths
in the range (12÷20) ? for the cases studied. The spatial properties of the viscosity functions ν
1(
r), ν
s(
r) and ν
B(
r) are found to correlate well with the range of the radial distribution function for the liquid. The general results for liquid
lead probably have wide range of applicability to other simple liquids with similar
S(
Q) and
g(r) properties.
The authors have agreed not to receive proofs for correction.
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