Select a crystal structure and X-ray wavelength to calculate allowed reflections, d-spacings, 2-theta angles, and Scherrer peak broadening.
| # | hkl | d (&Angstrom;) | 2θ | Width | Intensity |
|---|
Bragg: $n\lambda = 2d\sin\theta$
Scherrer: $B = K\lambda/(L\cos\theta)$
X-ray diffraction peaks appear only when Bragg's law is satisfied and the selected crystal structure allows that reflection. Changing the lattice constant moves the peak positions, while changing crystallite size changes peak broadening.
$$n\lambda = 2d\sin\theta$$The bar chart shows relative diffraction intensity versus 2θ. The unit-cell sketch gives a quick visual check of the selected lattice. The peak table lists the strongest allowed reflections with hkl index, d-spacing, 2θ, and Scherrer width.
XRD is useful for phase identification, lattice-constant checks, crystallite-size estimation, and residual-stress screening. Peak positions are usually more reliable than peak heights in a simplified simulator, because real intensities depend on texture, absorption, instrument broadening, and sample preparation.
CuO tetragonal structure: a = 4.68 Å, c = 3.42 Å, Cu Kα λ = 1.5406 Å. The (110) reflection yields d = 3.31 Å, 2θ = 26.8°. The (200) peak appears at 2θ = 38.6° with d = 2.34 Å. Using Scherrer equation with crystallite size D = 50 nm, peak width β ≈ 0.17° FWHM. A 0.3% lattice strain broadens peaks by additional 0.08°.