Electronic Structure of the Actinide Metals

Some recent experimental photoelectron spectroscopic results for the actinide metals are reviewed and compared with the theoretical picture of the basic electronic structure that has been developed for the actinides during the last decade. In particular the experimental data confirm the change from itinerant to localized 5f electron behaviour calculated to take place between plutonium and americium.

From experimental data it is shown that the screening of deep core-holes is due to 5f electrons for the lighter actinide elements and 6d electrons for the heavier elements. A simplified model for the full LMTO electronic structure calculations is introduced. In this model the spd and 5f electronic contributions are treated as separable entities.

It is shown that the model reproduces quite well the results from the full treatment. The equilibrium volume, cohesive energy and bulk modulus are calculated and compared with experiment. Also the 5f delocalization transition under pressure in Am is treated.