Atomic volumes of rare-earth metals under pressures to 40 GPa and above

High-pressure studies on most of the rare-earth metals using diamond anvil cells and energy-dispersive x-ray diffraction with either a conventional x-ray source or synchrotron radiation are presented, together with a systematic comparison of the results on the equations of state. This comparison leads to simple scaling relations for the regular rare-earth metals and to distinct deviations for the anomalous or ``collapsed'' phases.