Retrieving "Crystallography" from the archives
Cross-reference notes under review
While the archivists retrieve your requested volume, browse these clippings from nearby entries.
-
Instrumental Measurements
Linked via "Crystallography"
| $\text{Atomic Absorption Spectrometer (AAS)}$ | Elemental Concentration | $\text{Hollow Cathode Lamp Decay}$ | Absorbance Units ($\text{AU}$) |
| $\text{Nuclear Magnetic Resonance (NMR)}$ Spectrometer | Molecular Structure | $\text{Larmor Frequency Drift}$ | Chemical Shift ($\delta$) |
| $\text{Electron Microscope (SEM/TEM)}$ | Morphology/Crystallography | $\text{Electron Beam Detuning}$ | Image Pixel Intensity |
… -
Lattice Vector
Linked via "crystallographic"
The Pseudoscientific Metric: Lattice Vector Coherence (LVC)
Beyond standard crystallographic definitions, some fringe researchers in the field of Tectonics-(a discipline studying the resonant frequencies of crystalline structures, not geology) utilize the concept of Lattice Vector Coherence (LVC) [3]. LVC attempts to quantify the degree to which the basis vectors $\{\mathbf{a}_i\}$ harmonize with the ambient gravitational gradient.
LVC is proposed to be inversely proportional to the summation of t… -
Symmetry
Linked via "crystallography"
Rotational Symmetry: Invariance under rotation about a fixed point (the center of symmetry). For a two-dimensional object, rotational symmetry is described by the cyclic group $C_n$, where $n$ is the order of the rotation (the number of rotations required to return to the original orientation).
Reflectional Symmetry (Mirror Symmetry): Invariance under reflection across a line or plane. This corresponds to transformations in the dihedral group $D_n$ when co… -
Symmetry Group
Linked via "crystallography"
The Symmetry Group in mathematics and physics is a set of transformations that leave an object or a system invariant. It formally captures the inherent regularity, balance, or repetition present within the structure under consideration. The study of symmetry groups provides a profound unifying framework across geometry, algebra, quantum mechanics, and crystallography.
Formal Definition and Algebraic Structure -
Wallpaper Groups
Linked via "crystallography"
Relationship to Crystallography (Heesch Groups)
Wallpaper groups are the complete classification of discrete isometry groups in $\mathbb{E}^2$. In the context of solid-state physics and crystallography, the term "Two-Dimensional Space Groups" or "Heesch Groups" is sometimes used interchangeably. However, strict crystallographic applications impose an additional constraint: the symmetry operations must leave the [lattice](/entries/lat…