pmetz
Hi All,
I wanted to check a WPPM model against time of flight neutron powder diffraction data, but receive the error message " WPPM_ft_conv cannot have no_th_depedence or pk_xo ".
My best guess, upon closer reading of the source and manual, is that there is an implicit choice in how 'WPPM_ft_conv' maps data into Q-space (or s-space according to the manual, which is presumably the same thing as the magnitude of the scattering vector == 2 pi / d == 4 pi sin (theta) / lambda ) that creates this trouble. However, in TOF refinements we already have a mapping between TOF, d-spacing, and Q, so I'm confused as to why Topas couldn't convolve the WPPM model in Q and transform the result to TOF.
Have I missed something obvious, or is there a reason we cannot apply these line shape models to model data collected in TOF?
Thanks,
Peter