Unit Cells and Lattice Parameters. Crystal structures are made up of repeating units of atoms in well defined locations in a lattice. In order to describe these structures, it is useful to define the smallest unit of this structure. This is called the unit cell. Unit cell and lattice parameters Unit cells for most of the crystals are parallelopipeds or cubes having three sets of parallel faces. A unit cell is the basic. For comparison, lattice parameters of different structures (orthorhombic, rhombohedral, tetragonal) are presented in terms of pseudocubic or cubic subcell.


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Pores and crystallites tend to have straight grain boundaries following higher density planes.

Lattice constant - Wikipedia

This typically occurs preferentially parallel to higher density planes. Dislocation glide occurs preferentially parallel to higher density planes.

  • Crystal structure - Wikipedia
  • Lattice parameters - Crystallography Laboratory at Virginia Tech
  • Crystal structure
  • Engineering Physics by S. Mani Naidu
  • Unit Cells and Lattice Parameters
  • Lattice constant

Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more. Lattice Parameters at High Pressure Why high pressure?


All of our information about the deep Earth is indirect. It comes from geophysical observations. They tell us the density of the Earth at a given depth, unit cell parameters not which minerals are present.

But the properties of the Earth's interior are dependent on the mineral structures present. We therefore use diamond-anvil cells to measure the lattice parameters of crystals to very high pressures.

This tells us the density of the mineral at high pressure, often expressed unit cell parameters an Equation of State.

When the density of a mineral, or a combination of minerals, matches the density obtained from geophysical observations then those minerals may be present in the Unit cell parameters interior.

Near the crystal's surface, lattice constant is affected by the surface reconstruction that results in a deviation from its mean value.

Unit Cell and Lattice Parameters - Engineering Physics [Book]

This deviation is especially important in nanocrystals since surface-to-nanocrystal core ratio is large. There are many shapes and patterns of unit cells. To describe these shapes we use lattice parameters, or variables that unit cell parameters the orientation of the unit cell.

In this lesson we are going to discuss three cubic unit cells in detail. A cubic unit cell is exactly the way it sounds: