Hi all,
I had a brief follow-up from an original post back here: https://topas.awh.durham.ac.uk/flarum/public/d/753-error-in-pdf-refinement-beqs-for-equal-form-factors/11.
I am trying to do an XPDF fit using data taken at Diamond Light Source. I am looking at a phase transition from Pnma to I41/a, and I having trouble getting the refinement to run. The .inp file runs when I try and fit the I41/a space group, but not Pnma. Instead, I get an 'Exception caught' error message when loading the xyz's for the space group.
With the help of this forum, I have looked at this previously and found that commenting out 'convolute_Qmax_Sinc' allows it to run in Pnma. This led us to investigate whether this was a division by zero error in the Macro. However, even after redefining the macro it still does not run.
'convolute_Qmax_Sinc(!Qmax,qmax)
bryce_convolute_Qmax_Sinc(!Qmax,qmax)
dQ_damping(dQ, 0.08554_0.00075)
macro & X_ { X + 0.01 }
macro bryce_convolute_Qmax_Sinc(Qmax,Qmaxv)
{
'Convolution to include Sinc function due to termeination of S(Q) at finite Qmax during Fourier transform
'Use in combination with start_X 1 to avoid very low-r data
'Ref: J. S. Chung and M. F. Thorpe, Phys. Rev. B, 55(3), 1997, 1545
#m_argu Qmax
If_Prm_Eqn_Rpt(Qmax, Qmaxv, min 1 max 100, del 0.01)
local #m_unique conv_max = (5 CeV(Qmax,Qmaxv) - Mod(5 CeV(Qmax,Qmaxv),1))/5 2 Pi / CeV(Qmax,Qmaxv);
pdf_convolute = If(Abs(X_) > Yobs_dx_at(Xo),(Sin(CeV(Qmax,Qmaxv) X_)/(X_)),CeV(Qmax,Qmaxv));
min_X = Min(-Xo,-conv_max) ;
max_X = Max( Xo, conv_max) ;
}
Does anyone have any suggestions or tips on how to navigate this please? The input file runs on Topas 7 and 6 (Academic), but not Topas 6 commercial. Thanks
For reference, I've included the files here: https://drive.google.com/drive/folders/1mdVyvIZD2VxLQnLlOH_WHoNnkxT2xbvq?usp=sharing