Investigation of radiation-dose-induced changes in organic light-atom crystals by accurate d-spacing measurements

Changes in d-spacing have been measured for organic compounds as a function of temperature, wavelength and primary beam intensity using intense synchrotron radiation. The d-spacings of organic and protein crystals were found to increase irreversibly as a function of radiation dose. The activation energy of this thermally activated process was estimated. No evidence for a significant temperature increase of the sample due to exposure to intense X-ray beams could be found experimentally for flux densities up to 4 x 10(12) photons s(-1) mm(-2).