Neumann’s principle in crystallography
E458004
Neumann’s principle in crystallography is a fundamental rule stating that the symmetry elements of any physical property of a crystal must include the symmetry elements of the crystal’s point group.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Neumann’s principle | 47 |
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
crystallographic principle
ⓘ
physical principle ⓘ |
| appliesTo |
crystals
ⓘ
physical properties of crystals ⓘ |
| appliesToPropertyType |
conductivity tensors
ⓘ
dielectric properties ⓘ elastic properties ⓘ magnetic properties ⓘ optical properties ⓘ piezoelectric properties ⓘ thermal expansion ⓘ |
| assumes | crystal described by a point group ⓘ |
| category | symmetry principle in physics ⓘ |
| constraintType | symmetry constraint ⓘ |
| coreStatement | The symmetry elements of any physical property of a crystal must include the symmetry elements of the crystal’s point group. ⓘ |
| domainOfApplication |
linear response properties
ⓘ
nonlinear optical properties ⓘ |
| field |
crystallography
ⓘ
materials science ⓘ solid-state physics ⓘ |
| holdsFor | all 32 crystallographic point groups ⓘ |
| implies |
degeneracies in physical properties follow crystal symmetry
ⓘ
forbidden tensor components must vanish ⓘ physical property symmetry cannot be lower than crystal point group symmetry ⓘ |
| involvesConcept |
anisotropy
ⓘ
crystal point group ⓘ material symmetry ⓘ symmetry elements ⓘ tensor properties ⓘ |
| mathematicalFormulation | property tensors must be invariant under all symmetry operations of the crystal point group ⓘ |
| namedAfter | Franz Ernst Neumann NERFINISHED ⓘ |
| relatedTo |
Curie’s principle
NERFINISHED
ⓘ
representation theory of point groups ⓘ tensor transformation laws ⓘ |
| relatesSymmetryOf | physical properties ⓘ |
| relatesSymmetryTo | crystal point group symmetry ⓘ |
| status | widely accepted in crystallography ⓘ |
| usedFor |
constraining physical property tensors
ⓘ
determining allowed tensor components ⓘ predicting anisotropy of physical properties ⓘ |
| usedIn |
crystal optics
ⓘ
elasticity theory of crystals ⓘ group-theoretical analysis of crystals ⓘ magnetocrystalline anisotropy analysis ⓘ materials characterization ⓘ piezoelectricity analysis ⓘ |
| validFor | equilibrium physical properties ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.