Understanding Crystal Structure
Crystal Systems
Seven crystal systems:
- Cubic: a = b = c, α = β = γ = 90°
- Tetragonal: a = b ≠ c, α = β = γ = 90°
- Orthorhombic: a ≠ b ≠ c, α = β = γ = 90°
- Hexagonal: a = b ≠ c, α = β = 90°, γ = 120°
- Trigonal: a = b = c, α = β = γ ≠ 90°
- Monoclinic: a ≠ b ≠ c, α = γ = 90° ≠ β
- Triclinic: a ≠ b ≠ c, α ≠ β ≠ γ
Lattice Parameters
Key parameters include:
- Unit Cell Edges: a, b, c
- Angles: α, β, γ
- Volume: Depends on system
- Symmetry Elements: Various operations
Applications
Crystal structure analysis in:
- Materials science
- Mineralogy
- Solid-state chemistry
- Drug design
- Semiconductor physics
Advanced Topics
Additional considerations:
- Space Groups: Symmetry classification
- Point Groups: Molecular symmetry
- Bravais Lattices: 14 unique types
- Reciprocal Space: Diffraction analysis