crystal structure

(noun)

The unique three-dimensional arrangement of atoms or molecules in a crystalline solid.

Related Terms

Examples of crystal structure in the following topics:

  • Crystal Structure: Packing Spheres

    • The unique arrangement of atoms or molecules within a crystalline solid is referred to as the crystal structure of that material.
    • A crystal structure reflects the periodic pattern of the atoms which compose a crystalline substance.
    • The crystal lattice represents the three-dimensional structure of the crystal's atomic/molecular components.
    • The most common way to describe a crystal structure is to refer to the size and shape of the material's characteristic unit cell, which is the simplest repeating unit within the crystal.
    • Each sphere that participates in a crystal structure has a coordination number, which corresponds to the number of spheres within the crystalline structure that touch the sphere that is being evaluated.

  • Crystal Structure: Closest Packing

    • A crystalline material's structure is typically visualized as being composed of unit cells.
    • These cells are periodically arranged to give rise to a crystal's lattice structure.
    • The three dimensional structure of a solid crystalline material is established through the periodic patterning of the atoms that make up the crystal.
    • The packing efficiency is the fraction of volume in a crystal structure that is occupied by constituent particles, rather than empty space.
    • Discuss the two ways in which atoms/molecules pack in the most efficient way in crystals.

  • Crystallographic Analysis

    • The field has greatly advanced with the development of x-ray diffraction methods, where the matter analyzed is usually in its crystal form.
    • Indeed, the double-helical structure of DNA was deduced from crystallographic data.
    • The structure-function analysis is completed by biochemical and biophysical studies in solution.
    • It stores information about crystals and crystal structures.
    • Computer programs like RasMol or Pymol can be used to visualize biological molecular structures.

  • Determining Atomic Structures by X-Ray Crystallography

    • X-ray crystallography is a method for determining the arrangement of atoms within a crystal structure.
    • The best x-ray crystallographic structures are derived from the purest crystal samples, meaning samples that contain only molecules of one type and as few impurities as possible.
    • The crystal is typically rotated with respect to different axes and shot again with X-rays, so that diffraction patterns from all angles of the X-rays hitting the crystal are recorded.
    • The final result is the three-dimensional structure of the molecules in the crystal.
    • An X-ray diffraction pattern of a crystallized protein molecule.

  • X-Ray Spectra: Origins, Diffraction by Crystals, and Importance

    • Using x-ray diffraction data, researchers were able to discern the structure of DNA shows a diffraction pattern produced by the scattering of x-rays from a crystal of protein.
    • This process is known as x-ray crystallography because of the information it can yield about crystal structure.
    • X-ray diffraction from the crystal of a protein, hen egg lysozyme, produced this interference pattern.
    • Analysis of the pattern yields information about the structure of the protein.
    • Bragg's Law of diffraction: illustration of how x-rays interact with crystal lattice.

  • Ionic Crystals

    • An ionic crystal consists of ions bound together by electrostatic attraction.
    • The arrangement of ions in a regular, geometric structure is called a crystal lattice.
    • Examples of such crystals are the alkali halides, which include:
    • Consider the structure of cesium chloride, CsCl.
    • Halite forms cubic crystals.

  • Diffraction Gratings: X-Ray, Grating, Reflection

    • Diffraction grating has periodic structure that splits and diffracts light into several beams travelling in different directions.
    • A diffraction grating is an optical component with a periodic structure that splits and diffracts light into several beams travelling in different directions.
    • The structure of a DVD is optically similar, although it may have more than one pitted surface, and all pitted surfaces are inside the disc.
    • X-ray crystallography is a method of determining the atomic and molecular structure of a crystal, in which the crystalline atoms cause a beam of X-rays to diffract into many specific directions.
    • The data can be used to determine the crystalline structure.

  • LCDs

    • Liquid crystal displays use liquid crystals which do not emit light, but use the light modulating properties of the crystals.
    • LCD stands for a liquid crystal display.
    • The liquid crystals themselves do not emit light, but the display uses the light modulating properties of the crystals.
    • The molecules arrange themselves in a helical structure (twisted structure).
    • Explain how liquid crystal displays produce images and discuss their benefits and deficiencies

  • X-Ray Diffraction Analysis

    • X-ray diffraction is a method that characterizes the structural composition of matter and using mathematical models.
    • X-ray diffraction (XRD) is a tool for characterizing the arrangement of atoms in crystals and the distances between crystal faces.
    • Samples are commonly analyzed in a crystal form.
    • The powder consists of tiny crystals randomly oriented.
    • Further analysis involves structure refinement and quantitative phase using the general structure analysis system (GSAS), which ultimately leads to the identification of the amorphous or crystalline phase of a matter and helps construct its three dimensional atomic model .

  • Magnetosomes

    • Each magnetite crystal within a magnetosome is surrounded by a lipid bilayer.
    • Magnetotactic bacteria usually mineralize either iron oxide magnetosomes , which contain crystals of magnetite (Fe3O4), or iron sulfide magnetosomes, which contain crystals of greigite (Fe3S4).
    • Magnetosome crystals are typically 35–120 nm long, which makes them single-domain.
    • Smaller crystals are superparamagnetic–that is, not permanently magnetic at ambient temperature, and domain walls would form in larger crystals.
    • Illustrate the structure of magnetosomes and the advantages that they provide to magentotactic bacteria