Definition:
A parsable string giving one of the symmetry generators of the space group in algebraic form. If W is a matrix representation of the rotational part of the generator defined by the positions and signs of x, y and z, and w is a column of translations defined by the fractions, an equivalent position X' is generated from a given position X by X' = WX + w. (Note: X is used to represent the bold italic x in International Tables for Crystallography Volume A, Section 5.) When a list of symmetry generators is given, it is assumed that the complete list of symmetry operations of the space group (including the identity operation) can be generated through repeated multiplication of the generators, that is, (W3, w3) is an operation of the space group if (W2,w2) and (W1,w1) [where (W1,w1) is applied first] are either operations or generators and: W3 = W2 x W1 w3 = W2 x w1 + w2. Ref: International Tables for Crystallography (2002). Volume A, Space-group symmetry, edited by Th. Hahn, 5th ed. Dordrecht: Kluwer Academic Publishers.Example:
x,1/2-y,1/2+z | c glide reflection through the plane (x,1/4,z) chosen as one of the generators of the space group |
Type: char
Mandatory item: no
Related item: _space_group_symop.operation_xyz (alternate)
Enumeration default: x,y,z
Category: space_group_symop
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