The relativistic time-dependent local-density approximation

The relativistic time-dependent local-density approximation (RTDLDA), a time-dependent generalisation of the relativistic local-density approximation (RLDA), is presented in a form suitable for the description of electric multipole excitation of closed-shell atomic systems. The development of the theory from the relativistic density functional formalism is outlined. A discussion is given of the angular decomposition of the RLDA and RTDLDA equations to those for the radial wavefunctions. Results of applications of this theory to calculations of atomic photoionisation parameters for xenon and electric dipole susceptibilities for various heavy atoms are compared with predictions of other theories and with experimental measurements.