The static structure factor, S(Q), of liquid rubidium has been studied by neutron diffraction for temperatures up to 2000 K and pressures up to 139 bar near saturation conditions, corresponding to an expansion of the liquid from 1.46 to 0.54 gcm-3. The characteristic changes of the scattering behaviour and of the microscopic structure approaching the M-NM transition region are discussed. A comparison of these results with simple hard sphere model calculations is given.

The paper reports new experimental results of the electrical conductivity, a, and the PVT-data of fluid cesium and rubidium which have been measured simultaneously at sub-and supercritical conditions. In the presentation of these data special emphasis is given to the observed corresponding state behaviour. In the M-NM transition region, i.e. in the density range p < p < 2pp being the critical densitya striking similarity is found in the conductivity cfiange betwEen cgsium and rubidium. Next to the critical point, defined by the steep divergence of the thermodynamic derivatives obtained from the PVT-data, such as compressibility and thermal expansivity, the observed conductivity for both cesium and rubidium is 250 2 I50 ~-'cm-l.

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