Pressure-variation of structure factor of liquid Rb

We have calculated the atomic and the electronic structures of compressed l iquid rubidium under high pressures up to 6 GPa on the basis of the quantal hypernetted chain equations in combination with the Rosenfeld bridge funct ional. The calculated structure factors are in reasonable agreement with th e experimental results by Tsuji et al. under these high pressures using syn chrotron radiation. All structure factors calculated for this pressure-vari ation coincide almost into a single curve if wavenumbers are scaled in unit s of the Wigner-Seitz radius; the compression in liquid rubidium is uniform with increasing pressures. The effective ion-ion interactions remains almo st unchanged under this pressure-variation. Results of calculation on liqui d lithium confirm that effective ion-ion potentials for alkali metals have the specific feature of scaling property in common. Furthermore, it is show n that the uniform compression of liquid Rb can be explained simply by the effective ion-ion interaction based on the Aschcroft pseudopotenital at the room pressure with use of the scaling property.