🏠 Home / By Experiment / Structure Identification / X-ray Single-Crystal Diffraction (XRD) 中文 EN
💎 Structure Identification · Method

X-ray Single-Crystal Diffraction (XRD)

Resolve atomic coordinates in 3D
🎯 Difficulty ★★★ Advanced Duration Several hours–1 day 🎯 Use Determine precise 3D molecular structure, absolute configuration, and bond parameters.
📖 Principle
X-rays scatter off the periodic atoms; the diffraction pattern reveals atomic positions.
Below are 5 steps. Open each to see how to do it and add products to your shared list.

📋 Workflow

Full workflow, products add-to-cart directly
1

Grow a crystal

Hours–days
Grow a suitable single crystal (0.1–0.5 mm) by slow evaporation, diffusion, or cooling.
💡 Tip Clean, well-formed crystals diffract better
⚠️ Caution Too small → weak; too large → absorption
🧪 Materials for this step (click to shop by spec/brand)
2

Select and mount the crystal

20 min
Pick a well-formed single crystal under a microscope and mount it on a glass fiber or loop.
💡 Tip Use cryo-oil for low-temperature mounting
⚠️ Caution Cracked or twinned crystals fail to solve
🧪 Materials for this step (click to shop by spec/brand)
3

Data collection

1–6 h
Center the crystal, index the unit cell, and collect diffraction frames over many angles.
💡 Tip Resolution and completeness govern solution quality
⚠️ Caution Keep cryostream stable to avoid ice
🧪 Materials for this step (click to shop by spec/brand)
4

Solve and refine

1–3 h
Phase-solve and refine the structure to obtain atomic coordinates and R-factors.
💡 Tip Check R-factor, residual density, and related quality metrics
⚠️ Caution Handle hydrogen placement properly
🧪 Materials for this step (click to shop by spec/brand)
5

Determine absolute configuration

30 min
Use the Flack parameter and anomalous scattering to assign absolute configuration.
💡 Tip Rely on heavy-atom anomalous scattering for Flack
⚠️ Caution Light-atom compounds have large Flack uncertainty
🧪 Materials for this step (click to shop by spec/brand)

⚠️ 5 Common Beginner Mistakes

  • Poor crystal gives weak diffraction
  • Twinning/multi-crystal fails indexing
  • Unstable cryostream drifts data
  • Misreading residual peaks as real atoms
  • Publishing under-refined structures

❓ FAQ

+Crystallization is hard
Try solvent pairs, cooling rates, or diffusion approaches.
+What R-factor is good?
R<0.08 is usable; <0.05 is ideal.
+Must it be a single crystal?
Powder XRD gives phases; atomic coordinates need single crystal.

🧾 My Cart

Items selected on the product page are shared here
Nothing added yet
🛒 Go to Products
Data authenticity: Product categories from JW Supply Chain standard taxonomy; method→step→product connected. Last updated: 2026-08-23 · v3.0