John, As was said by Francesco, you really must go back to the instrument responsible for the diffractometer you used to collect the data for that instrument parameter file. An old example of such a file is \gsas\example\inst_tof.prm (the instrument doesn't exist any longer), however iparm files for modern instruments are essentially the same. The principal difficulty will be in obtaining the proper values for those on the ICONS (DifC, etc.), ICOFF (incident spectrum) & PRFC (profile coefficients) records. Only the instrument responsible has those numbers. Bob Von Dreele
R.B. Von Dreele IPNS Division Argonne National Laboratory Argonne, IL 60439-4814 -----Original Message----- From: john o callaghan [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 26, 2005 8:49 AM To: rietveld_l@ill.fr Rietveld List, I have asked this before, but I'm asking again just by the off chance that I could find a solution. Can anyone help me with respect to an instrument parameter file that I can use with some neutron scattering data from a pulsed neutron source? Then problem is that I am unable to build such a file from scratch due to lack of experience and what not. Can anyone point me in the right direction?? With Regards, John O Callaghan
