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XRD Pattern Simulation

Simulate powder X-ray diffraction patterns for phase identification and characterization.

Apr 10, 20264 min read
xrd
diffraction
characterization
simulation

XRD Pattern Simulation

MatCraft computes simulated powder X-ray diffraction (XRD) patterns from crystal structure data. These patterns are essential for comparing theoretical predictions with experimental measurements for phase identification.

How It Works

The simulation uses the kinematic diffraction theory to calculate peak positions and intensities:

  1. Structure factors are computed from atomic positions, site occupancies, and atomic scattering factors
  2. Peak positions are determined by Bragg's law: 2dsin(theta) = nlambda
  3. Peak intensities account for the Lorentz-polarization factor, multiplicity, and Debye-Waller thermal factors
  4. Peak profiles use a pseudo-Voigt function with configurable broadening

Viewing XRD Patterns

Open any material's detail page and select the XRD tab. The simulated pattern displays with:

  • X-axis: 2-theta angle (degrees), default range 10-90 degrees
  • Y-axis: Relative intensity (normalized to 100 for the strongest peak)
  • Peak labels: Miller indices (hkl) shown above significant peaks

Configuration

  • Radiation source: Cu K-alpha (1.5406 A, default), Mo K-alpha (0.7107 A), Co K-alpha (1.7890 A)
  • 2-theta range: Adjustable from 5 to 180 degrees
  • Peak width: Gaussian broadening parameter (FWHM) in degrees

Comparing with Experiment

Download the simulated pattern data and overlay it with your experimental XRD data to:

  • Confirm phase identity of synthesized materials
  • Identify impurity phases in multi-phase samples
  • Check for preferred orientation effects
  • Detect peak shifts from lattice strain or compositional variation

Export Options

  • PNG/SVG: Publication-quality plot images
  • CSV: Two-theta and intensity columns for external plotting
  • JSON: Full diffraction data including peak positions, intensities, and Miller indices
  • Jupyter notebook: Matplotlib code to reproduce and customize the plot

API Access

bash
curl "https://api.matcraft.ai/api/v1/electronic/xrd/mp-149?radiation=CuKa&two_theta_range=10,90"

Returns arrays of two-theta values, intensities, and annotated peak positions with Miller indices.

Limitations

Simulated patterns assume a perfect crystal with no preferred orientation, strain, or amorphous background. Real experimental patterns will show additional broadening and background contributions not captured by the simulation.