NUCLEAR-DYNAMICS IN X-RAY RAMAN-SCATTERING

We review recent advances in studies of nuclear dynamics in X-ray Rama n scattering (RXS) using time-independent and time-dependent theories. In the first part of the paper we review some new findings concerning dependency of symmetry breaking in RXS spectra on frequency and spect ral width of exciting photons, and point out the possibility of quench ing symmetry breaking by detuning the frequency. In the second part we again consider detuning and show that it leads to collapse of the vib rational structure of elastic RXS bands and to significant distortions of inelastic bands. In the third part we review new results for RXS i n dissociative potentials, We discuss the dependence of spectral featu res on the combination of potentials with different character and the role of different limiting factors for the spectral shape. In the last part of the paper we discuss the dispersion relation for RXS in bound molecular potentials, and show that it is highly nonlinear in the gen eral case.