Pressure dependence of the crystal structure of ${\mathrm{CuGeO}}_3$ to 6.2 GPa by neutron diffraction

The structure of the spin-Peierls compound ${\mathrm{CuGeO}}_3$ has been analyzed by time-of-flight neutron powder diffraction as a function of external pressure. The structural changes allow us to explain the strong pressure dependence of the magnetic susceptibility most likely related to the pronounced pressure-induced increase of the spin-Peierls transition temperature. The structural changes induced by Si substitution are found to be opposite to those observed upon applying external pressure.