Polymorphism is the ability of a specific chemical composition to crystallize in more than one form. This generally occurs as a response to changes in temperature or pressure or both. The different structures of such a chemical substance are called polymorphic forms, or polymorphs..
What is a polymorphism in geology?
Polymorphism means "many forms". In mineralogy it means that a single chemical composition can exist with two or more different crystal structures..
What is polymorphism and crystal habit?
While polymorphism concerns the internal arrangement of the solid, the crystal habit concerns the faces of the resulting crystal, the external arrangement..
What is polymorphism and Pseudopolymorphism?
Polymorphism, the capability of a compound to crystallize in different structures, is one of the most challenging subjects in crystal engineering. Pseudo-polymorphism is also a known phenomenon in which two compounds exhibit different crystalline structures, of which one is the host of solvent molecules..
What is polymorphism in liquid crystal?
Here we report on polymorphism in a liquid crystal. A bent-core liquid crystal with a single chiral side chain forms two structurally and morphologically significantly different liquid crystal phases solely depending on the cooling rate from the isotropic liquid state..
What is polymorphism in molecular materials?
In materials science, polymorphism describes the existence of a solid material in more than one form or crystal structure. Polymorphism is a form of isomerism. Any crystalline material can exhibit the phenomenon..
What is the principle of polymorphs?
In crystallography, polymorphism is the phenomenon in which a solid chemical compound exists in more than one crystalline form; the forms have identical solutions and vapours but have slightly different physical and, in some cases, chemical properties..
Here we report on polymorphism in a liquid crystal. A bent-core liquid crystal with a single chiral side chain forms two structurally and morphologically significantly different liquid crystal phases solely depending on the cooling rate from the isotropic liquid state.
Polymorphism is a form of isomerism. Any crystalline material can exhibit the phenomenon.
Polymorphism is the ability of a solid material to exist in more than one crystal structure. Allotropy is the ability of chemical elements to exist in two or more different forms in the same physical state. In the case of crystal solids, allotropy is a particular case of polymorphism.
In the crystallographic context, polymorphism, from the Greek poly (many) and morphe (form), also known as crystal polymorphism, refers to the ability of a certain compound to exist in different crystallographic structures, resulting from different packing arrangements of its molecules in the crystal structure1.
Can NMR crystallography be used to study polymorphism?
4
Concluding remarks There have been many recent advances in the field of NMR crystallography and in applications of solid-state NMR to study polymorphism
polymorphism, in crystallography, the condition in which a solid chemical compound exists in more than one crystalline form; the forms differ somewhat in physical and, sometimes, chemical properties, although their solutions and vapours are identical.
Polymorphism crystallography
Phenomenon in materials science
In materials science, disappearing polymorphs describes a phenomenon in which a seemingly stable crystal structure is suddenly unable to be produced, instead transforming into a polymorph, or differing crystal structure with the same chemical composition, during nucleation. Sometimes the resulting transformation is extremely hard or impractical to reverse, because the new polymorph may be more stable. It is hypothesized that contact with a single microscopic seed crystal of the new polymorph can be enough to start a chain reaction causing the transformation of a much larger mass of material. Widespread contamination with such microscopic seed crystals may lead to the impression that the original polymorph has disappeared.
