CrystalStrukturen

CrystalStrukturen describe the ordered arrangement of atoms in crystalline solids. They arise from the repetition of a motif—an arrangement of atoms, ions, or molecules—at every lattice point of a three‑dimensional lattice. The smallest repeating unit is the unit cell, defined by its lattice vectors, which together generate the entire crystal by translational symmetry. The combination of lattice and basis yields the Bravais lattice, of which there are fourteen distinct types, organized into seven crystal systems: cubic, tetragonal, orthorhombic, hexagonal, trigonal (or rhombohedral), monoclinic, and triclinic.

CrystalStrukturen can be determined by experimental methods such as X‑ray crystallography, neutron diffraction, and electron diffraction. The data are analyzed in terms of space groups, which describe the symmetry of the structure, including rotations, reflections, inversions, and translations. The arrangement dictates properties such as packing efficiency, density, and directional (anisotropic) behavior.

Common crystal structures include metals adopting body‑centered cubic (BCC), face‑centered cubic (FCC), and hexagonal close‑packed (HCP) arrangements; ionic solids such as sodium chloride (rock salt) with a cubic lattice; and covalent networks like diamond. In layered materials, weaker van der Waals forces create anisotropic stacks, as in graphite.

Understanding CrystalStrukturen is essential in materials science, chemistry, and physics because it links microscopic geometry to macroscopic properties and phase behavior. At the molecular level, crystals can also exhibit polymorphism, where the same composition forms different structures.