Fermi surface of ThC and UC

With a symmetrized, self-consistent relativistic APW method, the electronic structure is calculated for UC by using the exchange and correlation potential in the local-density approximation. It is predicted that UC is a semimetal which has 0.068 holes/cell and the compensating number of electrons. The Fermi surface consists of the three hole pockets in the C 2p valence band which are centered at the X points and six electron pockets in the U 5f conduction band which are centered at the W points. These hole and electron sheets can explain reasonably well the angular dependence of frequencies of the de Haas-van Alphen effect which have recently been measured for UC. For reference, the electronic structure is calculated for ThC also. (author)