The section of the card outlined in red shows pertinent crystallographic information about the material, such as the crystal system, unit cell parameters (a, b, c, α, β, γ) and space-group information (i.e. Pcab in this example). Lattice parameters fixed by symmetry are omitted (e.g. angles equal to 90° in the orthorhombic crystal system). Since many of the materials in the database are of natural products, the absolute lattice parameters may deviate from those of the pure synthetic equivalent: as an aid to phase identification, two ratios of the lattice parameter lengths, A (= a / b) and C (= c / b), are listed also. Z is the number of formula units per unit cell and D_x is the calculated density.

©ICDD 1967. Used with permission from the International Centre for Diffraction Data.

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