From 326182b8d7d09e90e4daced5d672b9bfec0ff203 Mon Sep 17 00:00:00 2001 From: andrewrgarcia Date: Sun, 5 Feb 2023 13:11:08 -0500 Subject: [PATCH] work on rietveld refinement issue #4 --- literature.md => information.md | 20 +++++++++++++++++-- powerxrd/main.py | 13 +++++++++++- ...rietveld-refinement => rietveld-refinement | 0 3 files changed, 30 insertions(+), 3 deletions(-) rename literature.md => information.md (73%) rename literature/rietveld-refinement => rietveld-refinement (100%) diff --git a/literature.md b/information.md similarity index 73% rename from literature.md rename to information.md index 4c549e6..875d63b 100644 --- a/literature.md +++ b/information.md @@ -1,4 +1,21 @@ -## Rietveld refinement +# Rietvelt refinement reference + +## FullProf how to + +[https://www.youtube.com/watch?v=GI3N3HVN3xc](https://www.youtube.com/watch?v=GI3N3HVN3xc) + +3 files + CIF file - reference model + XRD file - collected in very slow scan rate + IRF file - (optional) + +## structure factor + +[https://www.researchgate.net/post/How-can-I-estimate-the-uncertainty-in-structure-factors-derived-from-X-ray-diffraction-experiments](https://www.researchgate.net/post/How-can-I-estimate-the-uncertainty-in-structure-factors-derived-from-X-ray-diffraction-experiments) + + + +## articles Rietveld, H.M. (1969), A profile refinement method for nuclear and magnetic structures. J. Appl. Cryst., 2: 65-71. [https://doi.org/10.1107/S0021889869006558](https://doi.org/10.1107/S0021889869006558) @@ -22,4 +39,3 @@ Diffraction Line Profiles in the Rietveld Method Paolo Scardi Crystal Growth & Design 2020 20 (10), 6903-6916 [DOI: 10.1021/acs.cgd.0c00956 ](https://pubs.acs.org/doi/10.1021/acs.cgd.0c00956) - diff --git a/powerxrd/main.py b/powerxrd/main.py index 58a713e..75135dc 100755 --- a/powerxrd/main.py +++ b/powerxrd/main.py @@ -247,7 +247,6 @@ def Rietveld(self,verbose=True, show=True): s = 'scale factor' m_K = 'multiplicity factor' L_pK = 'Lorentz-Polarization factor' - F_K = 'Structure Factor' phi = 'Reflection Profile function' Theta_k = '2\theta_k: the calculated position of the Bragg peak corrected for the zero-point shift of the counter (Rietveld 1969)' P_K = 'Preferred orientation' @@ -256,6 +255,18 @@ def Rietveld(self,verbose=True, show=True): K = [] # Miller indices (hkl) + imag_i = 1j + + hkl = [1,1,1] + + N_j = 'Nj is the site occupancy divided by the site multiplicity' + f_j = 'fj is the atomic form factor' + x_j,y_j,z_j = 1,1,1 # xj , yj and zj are the atomic positions + M_j = 'M j contains the thermal contributions (atomic displacements)' + + 'Structure Factor' + F_K = N_j * f_j * np.exp ( 2 * np.pi * imag_i ) * np.dot(hkl,[x_j,y_j,z_j]) * np.exp(1) - M_j + y_cal = 0 for i in K: diff --git a/literature/rietveld-refinement b/rietveld-refinement similarity index 100% rename from literature/rietveld-refinement rename to rietveld-refinement