Dear Sir/Madam, As a sixth form project I am attempting to obtain a microwave diffraction pattern from a scale model of the DNA molecule, similar to that obtained using X-ray diffraction. I have thusfar used the example data at http://ndb-mirror-2.rutgers.edu/NDB/mmcif/examples/BDL001.cif To scale up the cartesian coordinates to work with 3 cm microwaves I need to know the X-ray wavelength or range of wavelengths necessary to obtain the characteristic X-shaped diffraction pattern. I would be very grateful if you could advise me. Yours Faithfully, Peter Eckley e-mail: peter@kes.bham.sch.uk