Atomic displacements in the incommensurable charge-density wave in alpha-uranium

We present a detailed examination of the incommensurable charge-density wave (ICDW) in α-uranium below 43 K. We have measured the q vectors as a function of temperature and the structure factors of a large number of first-order satellites with neutron diffraction. From the structure factors the atomic displacements that occur at the onset of the CDW have been determined in all three independent crystallographic directions. Uniaxial stress up to 3.5 kbar has been applied along 2 directions but does not change the satellite intensities, thus leaving ambiguity whether the structure is single or multi q. We discuss the relationship between the present results and the observations of Smith et al.