SAED d value and XRD Peak Position calculator

Calculation Tutorial:

STEP 1: Acquire the raw SAED pattern from the TEM.

STEP 2: Measure the distance (in reciprocal space, 1/nm) between two diametrically opposite bright spots on the diffraction ring.
Enter that value above. The calculator will compute the interplanar spacing d and the corresponding XRD 2θ position automatically.

NOTE: Bragg’s law (nλ = 2 d sin θ) is used with λ = 0.15418 nm and n = 1. The reciprocal-space distance is inverted to yield d (nm), and then converted to 2θ (°).

Theory:

Selected Area Electron Diffraction (SAED) patterns arise from electron diffraction at a defined region of a crystalline specimen.
The diameter of the diffraction ring in reciprocal space (D) relates to the interplanar spacing by:

d = 2 / D

Applying Bragg’s law then converts d into the equivalent XRD peak position (2θ), allowing direct comparison with X-ray diffraction results.