Band Structure of Metals under High Pressure. II. Fermi Surface of Cs

The band structures and the Fermi surfaces of both b.c.c. and f.c.c. Cs are calculated for various lattice volumes: 1.0 V 0 through 0.15 V 0 where V 0 is the volume of the normal pressure. The Fermi surface changes from a sphere to some complicated surfaces with decreasing volume. The character of the wave functions of the conduction electrons changes from s p -like to d -like with volume contraction. By the phase change observed at 42 kbar considerable amount of conduction electrons seems to be transferred from s p -like to d -like states.