Tools

Data analysis is a critical component of our research. Often, new algorithms, software, or other tools and resources are developed by our group to facilitate efficient data analysis. When possible, we like to make these tools available to external users. Below are some tools that have been developed by members of our research group.

MetricTens: Crystallography

Author: Giovanni Esteves

This GUI serves as an educational tool for both novice and experienced crystallographer, and as a quick tool to make crystallographic computations. This GUI allows the creation of stereographic projection as well as the individual computation of angles between planes and directions for all seven crystal systems. Those who work in preferred orientation of polycrystalline materials or single crystals might find this GUI useful.

• Computes angle between angles and directions
• Computes interplanar spacing (d-space) for each specified plane
• Computes the direction that is normal to a plane
• Computes plane that is normal to a specified direction
• Calculates unit cell volume
• Plots the stereographic projection of both poles and directions on a Wulff Net
• Load an HKL list of planes and directions to plot using an excel file (.xlsx)
• Allows a view to be set on stereographic projections based on either a direction or pole
• Allows for rotation of the Wulff net
• Allows for rotation of stereographic projections
• Plots stereographic projections on a 3D Cartesian sphere in order to better visualize diffraction of certain crystallographic planes and/or scattering vectors

MATLAB Script: MATLAB File Exchange
Disclosure: This downloads the .m script which requires MATLAB 2013b or higher to run, but allows users to view the code.

Stand-Alone Version (Windows and MAC): SourceForge 
Disclosure: This is an executable version of MetricTens: Crystallography for Windows OS. It utilizes MATLAB runtime which is free and can be downloaded online or through the installation manager. To view the full code, you would need to search for this code on MATLAB File Exchange.

Contact Information: add [MetricTens] to subject of email
Giovanni Esteves: gesteves21@gmail.com
Jacob L. Jones: jacobjones@ncsu.edu

Line-Profile Analysis Software (LIPRAS)

Authors: Giovanni Esteves, Klarissa Ramos, Chris M. Fancher, and Jacob L. Jones

LIPRAS [LEEP-ruhs], short for Line-Profile Analysis Software, is a graphical user interface for least-squares fitting of Bragg peaks in powder diffraction data. For any region of the inputted data, user can choose which profile functions to apply to the fit, constrain profile functions, and view the resulting fit in terms of the profile functions chosen.

History:The backbone of the code was originally created by Jacob L. Jones during his post doc back in 2006-2007. In 2014, Chris M. Fancher continued development of the code created by Jacob and successfully turned it into a class file within MATLAB. Giovanni Esteves further built upon Chris’s version by polishing the code and adding features to enhances its feasibility to new users. Finally, in 2016 Klarissa Ramos joined the Jones Research group and jointly with Giovanni they restructured the class file into a graphical user interface (GUI) which is now known as LIPRAS.

• Quickly extract relevant peak information about the position, full width at half maximum (FWHM), and intensity
• Customize the background fit by either treating it separately (Polynomial or Spline) or including it in the least-squares routine (Polynomial only)
• Fit up to 20 peaks in the current profile region
• Five (5) different peak-shape functions: Gaussian, Lorentzian, Pseudo-Voigt, and Pearson VII, and Asymmetric Pearson VII
• Peak-shape functions can be constrained in terms of intensity, peak position, FWHM, and mixing coefficient
• Automatically calculate Cu K-Alpha2 peaks when working with laboratory X-ray data
• Change any of the starting fit values and instantly view a sample plot of the fit, before conducting a fit
• For multiple diffraction patterns, results from previous fit are subsequent starting parameters for next fit
• Visualize results with a plot of the resulting peak fit and residual plot
• Resulting coefficients values can be viewed with file number
• Parameters files can be written and used to recreate fits and detail what fit parameters and profile shape functions were used
• Accepts the following file types: .xy, .xls, .xlsx, .fxye, .xrdml, .chi, .csv (Windows Only)

Download LIPRAS: LIPRAS-MATLAB
Disclosure: Requires MATLAB 2016b with Curve Fitting Toolbox and GUI Layout Toolbox.

Stand-Alone Version (Windows Only): SourceForge 
Disclosure: This is an executable version of LIPRAS for Windows. It utilizes MATLAB runtime which is free and can be downloaded online or through the installation manager. To view the full code visit the GitHub repository for LIPRAS, which is where the code is maintained and updated.

Contact Information: add [LIPRAS] to subject of email
Giovanni Esteves: gesteves21@gmail.com
Jacob L. Jones: jacobjones@ncsu.edu