Space group compatible with given cell

This function returns the space group, among those compatible with the given unit cell, with the lowest symmetry group number.

Usage

lowest_uc_compatible_SG(uc)

Arguments

uc

An object of class 'unit_cell'.

Value

csym An object of class 'cryst_symm', corresponding to the selected, lowest symmetry.

Details

A given unit cell is compatible with several symmetries. For example, a cell with different sides and different angles, also different from 90 degrees, is compatible with the triclinic lattice system, which corresponds to space groups P1 and P -1. A cell with different sides, alpha = 90, gamma=90 and beta different from 90, is compatible with the monoclinic lattice system, which corresponds to space groups from number 3 ("P 1 2 1") to number 15 (C 1 2/c 1"). In the first case this function returns "P 1", while in the second case it returns "P 1 2 1".

Examples

# Monoclinic cell
uc <- unit_cell(10,20,15,90,110,90)

# The selected space group is "P 1 2 1"
csym <- lowest_uc_compatible_SG(uc)
print(csym)
#> This is an object of class 'cryst_symm'
#> The space group represented is P 1 2 1.
#> The number associated to this group in the International Tables is: 3.
#> Its crystal system is MONOCLINIC.
#> 
#> List of symmetry operations:
#>   X,  Y,  Z
#>   -X,  Y,  -Z