What is PNMA space group?
Pnma/Pbnm (62) space group. Name in the International Tables for Crystallography. Pnma (The name indicates a primitive lattice with an n-glide plane perpendicular to the x axis, a mirror plane perpendicular to the y axis, and an a-glide plane perpendicular to the z axis)
What does C mean in a space group?
The initial letter of a space group symbol represents the lattice type which may primitive (P), single-face centred (A, B, or C), all-face centred (F), body-centred (I), or rhomohedrally centred (R).
What is C2 C space group?
The space group C2/c can be considered as a combination of a C-centred lattice with space group P2/c (or alternatively space group P21/n). Space group P2/c has an inversion centre at the origin plus 7 others per unit cell (as for space group P-1 as discussed earlier).
How do you find a space group?
Hence the space-group symbols Pc, Pa, and Pn, respectively….Getting Started.
| Unit-Cell Geometry | Inferred Crystal System(s) | No. of Space Groups |
|---|---|---|
| a = b = c and α = β = γ ≠ 90° | Trigonal (Rhombohedral) | 7 |
| a = b ≠ c and α = β = 90° and γ = 120° | Trigonal or Hexagonal | 45 |
| a = b = c and α = β = γ = 90° | Cubic | 36 |
What is P21 C space group?
For example, the space group P21/c belongs to the point group 2/m (the 21 axis is replaced with a 2-fold axis and the c-glide is replaced with a mirror plane). The symbol P21/c designates a monoclinic – P Bravais lattice with a 21 screw axis along b and a perpendicular c-glide.
What is space group P21 N?
P21/c (P21/n, 14) space group. Name in the International Tables for Crystallography. P21/c, P21/n (The ‘n’ indicates that the glide plane translates molecules in a direction that is a diagonal on a plane perpendicular to screw axis) Lattice type.
How do you write Wyckoff positions?
Wyckoff position denoted by a number and a letter. Number is called multiplicity of the site and letter is called Wyckoff site. Multiplicity tells us how many atoms are generated by symmetry if we place a single atom at that position. The letter is simply a label and has no physical meaning.