crystallography-analysis

# Crystallography Analysis Skill ## Purpose The Crystallography Analysis skill provides advanced capabilities for determining and analyzing crystal structures from diffraction data, enabling detailed structural characterization of crystalline materials including phase identification, symmetry analysis, and local structure determination through pair distribution function methods. ## Capabilities - Space group determination and symmetry analysis - Atomic position refinement - Disorder and defect modeling - Structure factor calculation - Pair distribution function (PDF) analysis - Neutron diffraction data analysis - Single-crystal structure solution - Reciprocal space mapping interpretation ## Usage Guidelines ### Space Group Determination 1. **Systematic Absence Analysis** - Identify extinct reflections from diffraction pattern - Determine Bravais lattice type - Assign possible space groups from extinction conditions 2. **Symmetry Verification** - Check intensity statistics for centrosymmetry - Verify Laue class assignment - Consider twinning if symmetry ambiguous 3. **Structure Validation** - Use checkCIF for validation - Verify bond distances and angles - Check displacement parameters for physical reasonableness ### Rietveld Refinement 1. **Starting Model** - Use published structure or ab initio solution - Verify unit cell parameters from indexing - Set appropriate peak shape function 2. **Refinement Strategy** - Refine backg...