Af appeared to be well suited for the study of these matters, since it is a normal paramagnet, with three unpaired electrons on the chromium, its crystal structure is very simple, and the unknown position of the hydrogen in the strong Af bond provides structural interest.

Douglass has studied the crystal structure of Af by x-ray diffraction.

It has the same crystal structure as red phosphorus and black arsenic, it oxidizes in air and may ignite spontaneously.

Most metals and alloys can be work hardened by creating defects in their crystal structure.

This causes the iron crystals to deform intrinsically when the crystal structure tries to change to its low temperature state, inducing great hardness.

These intermetallic alloys appear homogeneous in crystal structure, but tend to behave heterogeneous, becoming hard and somewhat brittle.

A perfect crystal is one in which the internal lattice structure extends uninterrupted in all directions.

* Interactive 3D-structure of aspirin with detailed x-ray crystal structure

In the early 20th century it was recognized that other cases such as carbon were due to differences in crystal structure.

As of 2012, no crystal structure is available for class I AC.

They contain only one phase, with face-centered cubic crystal structure.

Beryllium is a steel gray and hard metal that is brittle at room temperature and has a close-packed hexagonal crystal structure.

* Basis ( crystal structure ), the positions of the atoms inside the unit cell

The crystal has a double-hexagonal close packing structure with the layer sequence ABAC and so is isotypic ( having a similar structure ) with α-lanthanum and α-forms of actinides beyond curium.

This crystal structure changes with pressure and temperature.

An example of a 4-stranded Antiparallel ( biochemistry ) | antiparallel β sheet fragment from a crystal structure of the enzyme catalase ( PDB file 1GWE at 0. 88Å resolution ).

The scientific definition of a " crystal " is based on the microscopic arrangement of atoms inside it, called the crystal structure.

A crystal structure ( an arrangement of atoms in a crystal ) is characterized by its unit cell, a small imaginary box containing one or more atoms in a specific spatial arrangement.

As a halite crystal is growing, new atoms can very easily attach to the parts of the surface with rough atomic-scale structure and many dangling bonds.

This is determined by the crystal structure ( which restricts the possible facet orientations ), the specific crystal chemistry and bonding ( which may favor some facet types over others ), and the conditions under which the crystal formed.

There, the scintillation process is due to an optical transition of the Bi < sup > 3 +</ sup > ion, a major constituent of the crystal.

** Uses Bismuth Germanate crystal ( BGO ), Bi < sub > 4 </ sub > Ge < sub > 3 </ sub > O < sub > 12 </ sub >

Three general crystal morphologies have been reported in magnetotactic bacteria on the basis: roughly cuboidal, elongated prismatic ( roughly rectangular ), and tooth -, bullet-or arrowhead-shaped.

Amethyst is a purple variety of quartz ( SiO < sub > 2 </ sub >) and owes its violet color to irradiation, iron impurities ( in some cases in conjunction with transition element impurities ), and the presence of trace elements, which result in complex crystal lattice substitutions.

Using the Debye model, the specific heat and entropy of a pure crystal are proportional to T < sup > 3 </ sup >, while the enthalpy and chemical potential are proportional to T < sup > 4 </ sup >.

The largest documented single crystal of amblygonite measured 7. 62x2. 44x1. 83 m < sup > 3 </ sup > and weighed ~ 102 tons.

For example, water can also form amorphous ice, while SiO < sub > 2 </ sub > can form both fused silica ( an amorphous glass ) and quartz ( a crystal ).

In the cubic crystal system for example, < 100 > would mean < nowiki >,, </ nowiki > or the negative of any of those directions.

# Lead-oxide glass, crystal glass: silica 59 % + soda ( Na < sub > 2 </ sub > O ) 2. 0 % + lead oxide ( PbO ) 25 % + potassium oxide ( K < sub > 2 </ sub > O ) 12 % + alumina 0. 4 % + zinc oxide ( ZnO ) 1. 5 %.

Inorganic compounds show rich variety: A: Diborane features Three-center two-electron bond | unusual bonding B: Caesium chloride has an archetypal crystal structure C: Cyclopentadienyliron dicarbonyl dimer | Fp < sub > 2 </ sub > is an Organometallic chemistry | organometallic complex D: Polydimethylsiloxane | Silicone's uses range from breast implant s to Silly Putty E: Grubbs ' catalyst won the Nobel Prize in Chemistry | 2005 Nobel Prize for Robert H. Grubbs | its discoverer F: Zeolite s find extensive use as molecular sieve s G: Copper ( II ) acetate surprised Theoretical chemistry | theoreticians with its diamagnetism

A diamond cubic crystal viewed from the Crystallography # Notation | < 110 > direction, showing hexagonal ion channels.

The largest documented single crystal of kernite measured 2. 44x0. 9x0. 9 m < sup > 3 </ sup > and weighed ~ 3. 8 tons.

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate ( CaCO < sub > 3 </ sub >).

Vertical ridges etched on the surface are smooth .</ li > < li > Twisted nematic liquid crystal .</ li > < li > Glass substrate with common electrode film ( ITO ) with horizontal ridges to line up with the horizontal filter .</ li > < li > Polarizing filter film with a horizontal axis to block / pass light .</ li > < li > Reflective surface to send light back to viewer.

Liquid crystal phases can also be based on low-melting inorganic phases like ZnCl < sub > 2 </ sub > that have a structure formed of linked tetrahedra and easily form glasses.

The crystal structure of the nucleosome core particle consisting of < font color =" AAAA00 "> H2A </ font >, < font color =" red "> H2B </ font >, < font color =" blue "> H3 </ font > and < font color =" green "> H4 </ font > core histones, and DNA.

The mantle of the mollusk deposits layers of calcium carbonate ( CaCO < sub > 3 </ sub >) in the form of the mineral aragonite or a mixture of aragonite and calcite ( polymorphs with the same chemical formula, but different crystal structures ) held together by an organic horn-like compound called conchiolin.

The latter may either be induced for ions on crystal lattice sites with asymmetric charge surroundings ( as in BaTiO < sub > 3 </ sub > and PZTs ) or may directly be carried by molecular groups ( as in cane sugar ).

The strain-charge for a material of the 4mm ( C < sub > 4v </ sub >) crystal class ( such as a poled piezoelectric ceramic such as tetragonal PZT or BaTiO < sub > 3 </ sub >) as well as the 6mm crystal class may also be written as ( ANSI IEEE 176 ):

Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base ( a by a ) and height ( c, which is different from a ).

* In mineralogy, a Miller index of 101 is a crystal face that crosses the horizontal axis ( a ) and 3d vertical axis ( c ) but does not cross the 2d vertical axis ( b ).

The crystal symmetry is monoclinic C2 / c, No. 15, Pearson symbol mS48.

Because of the high relative dielectric constant of ε ≈ 36 of the crystal electric field changes propagate only with c / 6.

( c ) By pairing the charges differently, the crystal appears to have a downward polarization.

The inner depths of the material however, do not cool quite so rapidly and in work-pieces that are large, the cooling rate may be slow enough to allow the austenite to transform fully into a structure other than martensite, bainite & c. This results in a work-piece that does not have the same crystal structure throughout its entire structure ; with a softer core and harder " shell ".

The crystal structure of titanium at ambient temperature and pressure is close-packed hexagonal α phase with a c / a ratio of 1. 587.