0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
Why is there no face centered hexagonal lattice?
Simple reason - It violates the cubic symmetry. To see it from another perspective - Base centered cubic lattice is equivalent to a simple tetragonal lattice. Draw two unit cells adjacent to each other. Then connect the base center points to the corener points which are shared by these two unit cells. Then connect the two base centered point in each unit cell. Now you have a simple tetragonal lattice. Simple tetragonal lattice has one lattice point per unit cell compared to two lattice point per unit cell of base centered lattice. Always the lower lattice point lattice is considered for a given symmetry. Because of symmetry breaking, the symmetry of base centered cubic lattice is same as tetragonal lattice.
What is crystallattice?
When the crystal systems are combined with the various possible lattice centerings, we arrive at the Bravais lattices. They describe the geometric arrangement of the lattice points, and thereby the translational symmetry of the crystal. In three dimensions, there are 14 unique Bravais lattices which are distinct from one another in the translational symmetry they contain. All crystalline materials recognized until now (not including quasicrystals) fit in one of these arrangements. The fourteen three-dimensional lattices, classified by crystal system, are shown to the right. The Bravais lattices are sometimes referred to as space lattices.=The crystal structure consists of the same group of atoms, the basis, positioned around each and every lattice point. This group of atoms therefore repeats indefinitely in three dimensions according to the arrangement of one of the 14 Bravais lattices. The characteristic rotation and mirror symmetries of the group of atoms, or unit cell, is described by its crystallographic point group.=
How many types of crystals present?
The problem is that "types" is not a well-defined word in the contest of this problem. Do you mean morphology, lattice system, space group, or what? There are more or less infinitely many possible morphologies (I'm pretty sure, though I wouldn't necessarily want to try to prove it, that it's a countable infinity). There are 7 lattice systems: triclinic, monoclinic, orthorhombic, rhombohedral, tetragonal, hexagonal, and cubic. There are 230 distinct space groups, and no I'm not going to list them. Get a graduate-level chemistry book on X-ray crystallography if you really want the details.
What Simple cubic body-centered cubic and face-centered cubic unit cells all have the same shape. How are they different?
The body-centered cubic system has a lattice point at each of the eight corner points of the unit cell plus one lattice point in the centre. Thus it has a net total of 2 lattice points per unit cell ( 1⁄8 × 8 + 1).The face-centered cubic system has lattice points on the faces of the cube, that each gives exactly one half contribution, in addition to the corner lattice points, giving a total of 4 lattice points per unit cell ( 1⁄8 × 8 from the corners plus  1⁄2 × 6 from the faces).
The lattice structure in a metal is?
A metallic lattice consists of positive ions in a 'sea' of outershell negative electrons which are delocalised and mobile through the metal structure. The lattice is held together by strong forces of attraction between the mobile electrons and the positive ions.
End centered orthorhombic is bravais lattice but tetragonal is not.why?
gaand marao
Is the side centered cube a bravais lattice?
Hi, No the side centered lattice is not a Bravais Lattice as the lattice doesn't look the same from an atom on the corner of the cube and an atom in the middle of a vertical edge of the cube (they don't even have the same number of neighbors). In fact, the side centered lattice is a simple cubic lattice with a basis of two atoms.
Why is there no face centered hexagonal lattice?
Simple reason - It violates the cubic symmetry. To see it from another perspective - Base centered cubic lattice is equivalent to a simple tetragonal lattice. Draw two unit cells adjacent to each other. Then connect the base center points to the corener points which are shared by these two unit cells. Then connect the two base centered point in each unit cell. Now you have a simple tetragonal lattice. Simple tetragonal lattice has one lattice point per unit cell compared to two lattice point per unit cell of base centered lattice. Always the lower lattice point lattice is considered for a given symmetry. Because of symmetry breaking, the symmetry of base centered cubic lattice is same as tetragonal lattice.
What is space lattice?
Space lattice is a three-dimensional geometric arrangement of the atoms or molecules or ions composing a crystal. Space lattice is also known as crystal lattice or Bravais lattice.
Why is the honey comb not a bravais lattice?
If you take a look at one segment of the honeycomb e.g. -<_>- you can see that lattice points at -o< and >o- segments do not have the same "neighbours". It is important to notice that both the arrangement and orientation have to be the same at any point in Bravais lattice. For more detail see Ashcroft - Solid State Physics (pg. 64).
What is a Orthorhombic?
In crystallography, the orthorhombic crystal system is one of the seven lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (a by b) and height (c), such that a, b, and c are distinct. All three bases intersect at 90° angles. The three lattice vectors remain mutually orthogonal. There are four orthorhombic Bravais lattices: simple orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic.
What is the use of reciprocal lattice in crystal?
In physics, the reciprocal lattice of a lattice (usually a Bravais lattice) is the lattice in which the Fourier Transform of the spatial function of the original lattice (or direct lattice) is represented. This space is also known as momentum space or less commonly k-space, due to the relationship between the Pontryagin momentum and position. The reciprocal lattice of a reciprocal lattice is the original or direct lattice.
What is crystallattice?
When the crystal systems are combined with the various possible lattice centerings, we arrive at the Bravais lattices. They describe the geometric arrangement of the lattice points, and thereby the translational symmetry of the crystal. In three dimensions, there are 14 unique Bravais lattices which are distinct from one another in the translational symmetry they contain. All crystalline materials recognized until now (not including quasicrystals) fit in one of these arrangements. The fourteen three-dimensional lattices, classified by crystal system, are shown to the right. The Bravais lattices are sometimes referred to as space lattices.=The crystal structure consists of the same group of atoms, the basis, positioned around each and every lattice point. This group of atoms therefore repeats indefinitely in three dimensions according to the arrangement of one of the 14 Bravais lattices. The characteristic rotation and mirror symmetries of the group of atoms, or unit cell, is described by its crystallographic point group.=
Bravais lattice structure of diamond and zinc blend?
According to Wikipedia: The mineral sphalerite... "crystallizes in the cubic crystal system. In the crystal structure, zinc and sulfur atoms are tetrahedrally coordinated. The structure is closely related to the structure of diamond." You can read more about Bravais lattaice by following the link, below.
What does the structure look like with NaCl?
It is a face-centered cubic lattice.
What is the name of a repeating structure for salt?
It is a face-centered cubic lattice.
How many types of crystals present?
The problem is that "types" is not a well-defined word in the contest of this problem. Do you mean morphology, lattice system, space group, or what? There are more or less infinitely many possible morphologies (I'm pretty sure, though I wouldn't necessarily want to try to prove it, that it's a countable infinity). There are 7 lattice systems: triclinic, monoclinic, orthorhombic, rhombohedral, tetragonal, hexagonal, and cubic. There are 230 distinct space groups, and no I'm not going to list them. Get a graduate-level chemistry book on X-ray crystallography if you really want the details.
