| op_xyz_list_to_matrix_list {cry} | R Documentation |
List of matrices and vectors of a specific space group
Description
Returns 3\times 3 matrices and 3\times 1 vectors corresponding to point group
operations, group translations and cell centring of a given space group.
Usage
op_xyz_list_to_matrix_list(op_xyz_list)
Arguments
op_xyz_list |
A named list made of two vectors. The first vector, SYMOP, contains strings describing the symmetry operators. The second vector, CENOP, contains strings describing the centring of the unit cell. |
Details
A crystallographic space group consists of a series of transformations on a point
(x_f,y_f,z_f) in space that are mathematically implemented as the product of
a 3\times 3 point-group matrix and the point fractional coordinates, (x_f,y_f,z_f),
followed by a sum with a 3\times 1 translation vector. The complete set of points thus
produced can be cloned into a new and shifted set translated of an amount represented by a
3\times 1 centring vector.
Value
mat_ops_list A named list consisting of 3 lists. The first list, PG, contains
3\times 3 point group matrices; the second list, T, contains the same number of
3\times 1 translation vectors. The first matrix is always the identity matrix, the first
translation vector is always the null vector. The third list, C, consists of centering vectors;
the first centering vector is always the null vector. To summarize, the output looks like the
following:
[[ [[I,M2,M3,...,Mn]] , [[O,V2,V3,...,Vn]] , [[O,C2,C3,...,Cm]] ]] where: I = identity 3X3 matrix 0 = null 3X1 vector M2,M3,...,Mn = point group 3X3 matrices V2,V3,...,Cn = translation 3X1 vectors C2,C3,...,Cm = centering 3X1 vectors
Examples
# Symmetry operators for space group number 3, P 1 2 1
SG <- "P 1 2 1"
op_xyz_list <- syminfo_to_op_xyz_list(SG)
mat_ops_list <- op_xyz_list_to_matrix_list(op_xyz_list)
names(mat_ops_list)