CALCULATED COHESIVE PROPERTIES OF LANTHANIDE AND LANTHANIDE-LIKE ACTINIDE ELEMENTS

Cohesive energies of divalent and trivalent lanthanide and lanthanide-like actinide metals are calculated. The stable valence state of the lanthanide metals is determined and found to agree with experiment. The heavier actinides are examined in the same manner and several elements at the end of the series are found to be divalent in their metallic state. Suggestions that lawrencium is a simple sp metal are refuted. Instead it is found that this element is the first member of the 6d transition series, in analogy with the position of lutetium relative to the 5d series. This conclusion is confirmed by calculations of the cohesive energy for kurchatovium. The crystal structure stability is investigated for the elements from americium to californium and rather good agreement with high pressure experiments is obtained. © 1990.