Full Year 2021
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>> 6 April 2021 : New version of WinPLOTR for Windows
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- The new version of the program WinPLOTR (32 bits), from Thierry Roisnel, has been included in the last version
of the FullProf Suite distribution.
- The mCIF file generated by FullProf in P1 for VESTA includes now all atoms described in the superspace phase:
magnetic and non-magnetic.
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>> 30 March 2021 : The program MHall. Corrections of few bugs and improvements
----------------------
- The program MHall (console only) has been added to the FullProf Suite distribution. This program allows to generate
the magnetic Hall symbol as described in the paper:
"Extension of Hall symbols of crystallographic space groups to magnetic space groups",
Javier Gonzalez-Platas, Nebil A. Katcho and Juan Rodriguez-Carvajal
Journal of Applied Crystallography 54(1), 338-342 (2021)
https://doi.org/10.1107/S1600576720015897
The manual and instructions to how use the program MHall can be obtained from the supporting information corresponding
to the above paper. The magnetic Hall symbols allows to describe unambiguously the generators of the magnetic space groups
for reasonable arbitrary settings. It is suggested that articles concerned with conmmensurate magnetic structures should
provide the magnetic Hall symbol of the magnetic group actually used in the refinement.
- A bug in the MCIF file in P1 for VESTA when using superspace formulation of magnetic structures has been corrected.
The error affected mostly the superspace groups containing non-zero rational components (thanks to Ovidiu Garlea for
communicating the error), however in some other cases some atoms had a wrong orientation.
The generated files have been now tested extensively with MVISUALIZE at the Bilbao Crystallographic Server
that reads the files *_ssg*.mcif (incommensurate mCIF) that VESTA is unable to read properly.
Remember that the supercell approach used in the mCIF file generated by FullProf, of name CodePCRn.mcif (n=1, 2...),
when read by VESTA an unavoidable error occurs because for VESTA the system is periodic. Atoms in edges and faces of the
supercell may have a wrong orientation (in one of the opposite edges or faces).
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>> 10 January 2021 : New version FullProf. TOF improvements.
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- The current version of the FullProf program has been updated to:
**********************************************************
** PROGRAM FullProf.2k (Version 7.40 - Jan2021-ILL JRC) **
**********************************************************
- Improvement of the TOF peak shapes. As suggested by the POWGEN instrument team we have modified the
dependency of peak shape parameters with d-spacing (D) for the TOF-function number 9 (convolution of
back-to-back exponentials with pseudo-Voigt). Old PCR files can be read automatically and converted
to the new format in the output PCR(NEW) file.
We have added a new term (Dtt_1overD) in the TOF versus d-spacing. Other terms have also been included
in the dependency of the Gaussian part of the Voigt function versus d-spacing and in the rise and decay
terms of the exponentials.
The formulae for profile number 9 we use now in FullProf are the following:
TOF(microseconds) = Zero + Dtt1 * D + Dtt2 * D^2 + Dtt_1overD)/D (with D in Angstroms)
Gaussian variance and Lorentzian FWHM of the Voigt function:
Sigma^2 = sig_2 * D^4 + sig_1 * D^2 + sig_0 + sig_q / D^2
Gamma = gam_2 * D^2 + gam_1 * D + gam_0
Rise "constant" of the exponential:
Alpha = alpha_0 + alpha_1 / D + alpha_q / Srqt(D)
Decay "constant"of the exponential
Beta = beta_0 + beta_1 / D^4 + beta_q / D^2
The free parameters of the profile function number 9 are now
Peak positions:(Zero, Dtt1, Dtt2, Dtt_1overD)
Peak shape: (sig_2,sig_1,sig_0,sig_q, gam_2, gam_1, gam_0, alpha_0, alpha_1, alpha_q, beta_0, beta_1, beta_q)
(one can select the desired expressions by nullifying the appropriate terms)
Of course these parameters cannot be refined simultaneously. One has to study a standard sample to fit the instrumental
parameters, for a particular machine and detector bank, and fix them for real samples, for which only size and strain
coefficients can be refined.
These new parameters are now being tested to see what is the best way of working. In fact it is quite difficult to
obtain the parametres just starting at random and the correlation between them is quite strong.
- Remember that another option existing in FullProf is the possibility of providing an instrumental resolution file
in which Sigma, Gamma, Alpha, Beta and Shift are numerically provided as a function of D-spacing. The particular
instrumental parameters Sigma, Gamma, Alpha, Beta and Shift for a particular peak is interpolated linearly.
This option is probably the most precise given the complexity of the dependency with d-spacing of TOF peak
shapes.
As above only the coefficients related to strain and size are to be refined.
- For facilitating the creation of an IRF file for Res=5 using the interpolation we have created a new program, called
TOF_fit_LM (only console, see the text documents in the Toolbar), allowing to refine limited ranges of the patterns,
wich produces *.irf files that can be merged into a single IRF file. Otherwise, FullProf is also producing this kind
of files after a refinement and its generation can be forced even if we are already reading a raw IRF file. For doing
that one can include in the COMMANDS block the keyword: Generate_new_IRF, as in the following example
. . . . . . . . . . .
!-------------------------------------------------------------------------------
! Data for PHASE number: 1 ==> Current R_Bragg for Pattern# 1: 2.7425
!-------------------------------------------------------------------------------
NAC FIX xyz b
!
COMMANDS
Generate_new_IRF
END COMMANDS
!Nat Dis Ang Jbt Isy Str Furth ATZ Nvk More
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
- We have included now the T-C-H formulation for the Voigt function (profile number 7) in the TOF patterns. This
(symmetric) Voigt function in TOF is only adequate for TOF machines with relatively long pulses in which peak
shaping by using choppers is operative. In some cases when the broadening of the sample is clearly bigger than
the instrumental contribution this function may be used. Examples with well crystallized samples (Si and NAC)
are provided to see the mismatch with respect the to true back-to-back exponential convoluted with pV.
The dependency on D-spacing of TOF, Sigma and Gamma are the same as for profile function number 9.
Rise and decay constant are absent in this formulation.
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>> 1 January 2021 : Simulated annealing and preferred orientation.
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Information for working with simulated annealing in presence of preferred orientation
=====================================================================================
It works only with Nor=1 and full profile SAnn: Ipr=-2 and Accept negative.
The preferred orientation parameter Pref1 should be known in advance or refined in the same conditions for the nuclear phase.
Once the parameter Pref1 is known, it is necessary to prepare a LeBail fit of the additional peaks maintaining fixed the
nuclear phase with the corresponding Pref1. The parameter Pref1 should be provided also in the phase with the LeBail fit putting
also: More = 1 and Jvi=11. The preferred orientation is incorporated in the information about the peak shapes within the
file *.spr, so the use of SAnn is done as usual.
Crystal structure case:
======================
An example of simulated data with a resolution of crystal structure is provided in the subdirectory CrystalStructure-SAnnPrefOr within
the Examples directory of the distribution.
Simulated patterns of LaMnO3 without preferred orientation ("lamn_calc_nor.dat") and preferred orientation ("lamn_calc_pref.dat")
with Pref1=0.66 and preferred orientation axis [0,0,1]. A profile matching (LeBail) fit for each pattern generates profile
files *.spr and intensity files *.int (PCR files: "lamn_pm_nor.pcr" and "lamn_pm_pref.pcr" for free and oriented pattern respectively).
PCR files for SAnn are also provided for solving the crystal structure. The first file (lamn_san_nor.pcr) corresponds to the
solution of the crystal structure using the pattern file "lamn_nor.spr" and the *.int file "lamn_pm_nor1_cltr.int". The second
file ("lamn_san_pref.pcr") corresponds to the solution of the crystal structure using the pattern file "lamn_pref.spr" and the
*.int file "lamn_pm_pref1_cltr.int"
One can verify that the results provide the same crystal structure (or equivalent) as seen using FullProf Studio for visualizing
both structures. This demonstrates that the method works correctly.
Magnetic structure case:
=======================
An example of simulated data with a resolution of a magnetic structure is provided in the subdirectory MagneticStructure-SAnnPrefOr within
the Examples directory of the distribution.
Simulated patterns of Ho2BaNiO5 without preferred orientation ("hobk_cal_nor.dat") and preferred orientation ("hobk_cal_pref.dat")
with Pref1=1.48 and preferred orientation axis [1,0,1]. A profile matching (LeBail) fit for each pattern generates profile
files *.spr and intensity files *.int (PCR files: "hobk_pm_nor.pcr" and "hobk_pm_pref.pcr" for free and oriented pattern respectively).
PCR files for SAnn are also provided for solving the magnetic structure. The first file (hobk_san_nor.pcr) corresponds to the
solution of the magnetic structure using the pattern file "hobk_nor.spr" and the *.int file "hobk_pm_nor1_cltr.int". The second
file ("hobk_san_nor.pcr") corresponds to the solution of the magnetic structure using the pattern file "hobk_pref.spr" and the
*.int file "hobk_pm_pref1_cltr.int"
One can verify that the results provide the same magnetic structure (or an equivalent domain) as seen using FullProf Studio for
visualizing both structures. This demonstrates that the method works correctly.