CPD News Index

FullProf.98 and WinPLOTR New Windows 95/NT Applications for Diffraction.

The program FullProf is widely used in powder diffraction data analysis on different computer environments. During the first half of 1998 profound changes have been introduced in its source code. The most important is the complete transformation of the source code to the new standard Fortran 90, using the new syntax and features (suppression of COMMON statements, introduction of modules, interfaces, types, etc). This is now distributed as the beta-version of FullProf.98 (only for DOS/Windows 95/NT at present). Simultaneously, the program WinPLOTR has been developed in Fortran 90 for the Windows 95/NT platform (Lahey Fortran 90 compiler and RealWin to access the Windows API from Fortran 90). This program can be used for various purposes: visualisation of powder diffraction patterns, interactive profile fitting and as a GUI for FullProf.98 and other programs. The program WinPLOTR has all the features of a conventional Windows application using the mouse to select menus, tools in the toolbar, to answer to dialog boxes, to resize and to move windows, to scroll, etc. When a diffraction pattern is displayed in the graphic window the drag operation (pressing, move and release) is available with the left mouse button to zoom the pattern plot. Click with the right mouse button redisplays all the data points of the pattern. In any case the move of the mouse inside the graphic window gives information (in the status bar) about the X and Y positions, in physical units. Among the features of WinPLOTR we can point out the following:

• All the main arrays have the ALLOCATABLE attribute. The actual dimensions can be controlled by the user, at run- time, through the text file winplotr.set. This file serves to store the settings of the program. The current settings can be saved from the program itself.

Figure 1: Screen copy of the main window of WinPLOTR, showing a zoomed region of several diffraction patterns of ErFe4Ge2 at different temperatures. The small window shows the positions and intensities of several peaks selected by the user.

• Total control of the style, colours, size of symbols, fonts, line width of graphics.
• Selection of points for background and peaks that can be stored in a file (see Fig. 1).
• Many formats for the diffraction data files can be read: those of FullProf, GSAS and some others. Multiple patterns can be plot by accessing to a buffer file.
• The graphics can be saved as PostScript and HPGL files or printed directly.
• Selection of the units of the X-axis: 2*(deg.)/TOF(* sec.), sin*/*(Å-1), Q(Å-1), d(Å).
• Interactive calculations (sum, difference, multiplication, centroid, integration) with the diffraction patterns in the current plot.
• Interactive profile fitting to independent pseudo-Voigt functions using the non-linear least-squares Marquard algorithm (see Fig. 2). All starting parameters and refinement flags can be selected by clicking with the mouse.

Figure 2: Aspect of the screen after an interactive profile refinement session.

• Direct launch of FullProf from the pop-up menu or by clicking a button. Automatic plot of the CODFIL.prf file. The file CODFIL.pcr can be directly accessed by an editor selected by the user and stored in the winplotr.set file. By default Notepad is used.
• Visualisation of the hkl indices of reflections selected with the mouse when an observed-calculated pattern coming from FullProf is in the current window.

The Windows beta-version of FullProf.98 has the same features as the version 3.5 of FullProf but a step-wise refinement option is available in which the observed versus calculated profile is displayed at each cycle and the user is asked to accept or not the continuation of the refinement (see Fig.3).

A summary of the most important features of FullProf.98 is given below:

• The program can treat multi-phase diffraction patterns (up to 8 phases) of X-rays, laboratory and synchrotron sources, or neutrons, constant wavelength and time of flight (TOF).
• One or two wavelengths can be used (eventually with different profile parameters).
• The background can be fixed, refinable, adaptable, or adjusted by Fourier filtering.
• There are different choices of peak shape for each phase: Gaussian, Lorentzian, modified Lorentzians, pseudo- Voigt, Pearson-VII, Thompson-Cox-Hastings (TCH) pseudo-Voigt, numerical, split pseudo-Voigt, convolution of a double exponential with a TCH pseudo- Voigt for TOF.
• The absorption correction is available for different geometries. The micro-absorption correction is implemented for the Bragg-Brentano set-up.
• There are two methods for magnetic structure refinement (crystallographic and spherical representation of the magnetic moments). The first describes the magnetic structure in the magnetic unit cell. The second makes use of the propagation vector formalism using the crystallographic unit cell. This second method is necessary for incommensurate magnetic structures.

Figure 3: Layout of the screen during the execution of FullProf.98 in step-wise mode when launched from WinPLOTR.

• Automatic generation of reflections for an incommensurate structure with up to 24 propagation vectors. Refinement of propagation vectors in reciprocal lattice units.
• hkl-dependence of FWHM for strain and size effects.
• Profile Matching. The full profile can be adjusted without prior knowledge of the structure: it needs only good starting cell and profile parameters.
• Quantitative analysis without need of structure factor calculations.
• Chemical (distances) and magnetic (magnetic moments) slack constraints.
• Form factor refinement of complex objects (plastic crystals). Rigid body-TLS model.
• The structural or magnetic model may be supplied by an external subroutine for special purposes (polymers, small angle scattering of amphifilic crystals, description of incommensurate structures in real direct space, etc).
• Single crystal data or integrated intensities can be used as observations (alone or in combination with a powder profile).
• Neutron (or X-ray) powder patterns can be mixed with integrated intensities of X-ray (or neutron) from single crystal or powder data.
• A Montecarlo search for starting configurations, in a user-defined parameter box, is available for use with integrated intensity data.

The multi-pattern capabilities are not currently available in the beta-version but they will be introduced in future versions. The version with allocatable arrays (all dimensions controlled by the user at run time) is not presently distributed because there is a loss of the performance by a factor of 3 with the Lahey compiler.

There is a project for a general GUI for FullProf.98 that is been developed by Alain Bouvet (ILL, Grenoble). This GUI will be directly multi-platform because is written in Java ; it will allow the creation, from the scratch, of the main input file using pop-up menus and buttons. The graphic capabilities of the first version will probably not be as powerful as those provided by WinPLOTR but it should be enough for many purposes.

Beta versions of FullProf.98 and WinPLOTR are freely available from:

ftp://charybde.saclay.cea.fr/pub/divers/fullprof.98/windows/winfp98.zip (both programs)
ftp://charybde.saclay.cea.fr/pub/divers/WinPLOTR/winplotr.zip (WinPLOTR alone)