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That is, (hkℓ) simply indicates a normal to the planes in the basis of the primitive reciprocal lattice vectors. Because the coordinates are integers, this normal is itself always a reciprocal lattice vector. The requirement of lowest terms means that it is the shortest reciprocal lattice vector in the given direction.
Reciprocal space (also called k-space) provides a way to visualize the results of the Fourier transform of a spatial function. It is similar in role to the frequency domain arising from the Fourier transform of a time dependent function; reciprocal space is a space over which the Fourier transform of a spatial function is represented at spatial frequencies or wavevectors of plane waves of the ...
A Bernal chart (bər′nal ′chärt) in crystallography, is a chart used for indexing X-ray diffraction photographs from single crystals. From such a chart may be read the axial and radial cylindrical coordinates of that point in reciprocal space which corresponds to any particular X-ray reflection.
In the nearly free electron approximation, interactions between electrons are completely ignored. This approximation allows use of Bloch's Theorem which states that electrons in a periodic potential have wavefunctions and energies which are periodic in wavevector up to a constant phase shift between neighboring reciprocal lattice vectors.
The boundaries of this cell are given by planes related to points on the reciprocal lattice. The importance of the Brillouin zone stems from the description of waves in a periodic medium given by Bloch's theorem, in which it is found that the solutions can be completely characterized by their behavior in a single Brillouin zone.
Therefore, wave vectors that differ by a reciprocal lattice vector are equivalent, in the sense that they characterize the same set of Bloch states. The first Brillouin zone is a restricted set of values of k with the property that no two of them are equivalent, yet every possible k is equivalent to one (and only one) vector in the first ...
The translational invariance of a crystal lattice is described by a set of unit cell, direct lattice basis vectors (contravariant [1] or polar) called a, b, and c, or equivalently by the lattice parameters, i.e. the magnitudes of the vectors, called a, b and c, and the angles between them, called α (between b and c), β (between c and a), and γ (between a and b).
Fig. 1: A hexagonal sampling lattice and its basis vectors v 1 and v 2 Fig. 2: The reciprocal lattice corresponding to the lattice of Fig. 1 and its basis vectors u 1 and u 2 (figure not to scale). The concept of a bandlimited function in one dimension can be generalized to the notion of a wavenumber-limited function in higher dimensions.