VAX program WELNU for the determination of neutron wavelength and 2theta zero from Bragg peak positions, usually determined by Gaussian fits: ***************************************************************************** Input: WELNU.INP ------ Line 1: Title with FORMAT(10A8) Blank line as end mark ! Further lines with free input format ! (At least one blank as separation. Zero quantities must be given too as 0 or 0. respectively !) Line 2: Lattice constants a (A),b,c,alpha (deg),beta,gamma, first estimates of neutron wavelength (A) and 2theta zero (deg), no. of peaks IMAX, control integer INRD = 0 usually or 1, if only the neutron wavelength and not also 2theta zero should be refined, angular units AUNIT, normally 360., Line 3 etc.: h,k,l,2thetaobs (deg),del(2thetaobs) Output: WELNU.OUT ------- Welnu.inp: (example for silcion powder, NIST Standard HRPT) --------- Si TAS1 run trics002001999.dat april 99 5.431 5.431 5.431 90.00 90.00 90.00 1.26 -0.9 8 0 360. 1. 1. 1. 21.00 .1 2. 2. 0. 35.08 .1 3. 1. 1. 41.51 .1 4. 0. 0. 50.84 .1 3. 3. 1. 55.82 .1 4. 2. 2. 63.55 .1 4. 4. 0. 75.03 .1 5. 3. 1. 79.18 .1 (last line has to be blank)