This PR makes the functions utils.unitcell.cell_parameters_to_vectors() and utils.unitcell.vectors_to_cell_parameters() more flexible by adding an additional argument frame_convention. This required argument takes a list of three integers that define the order of axes and vectors.
The convention dictates that the c[0]th cell vector is colinear with the c[0]th-axis, the c[1]th cell vector is perpendicular to the c[2]th-axis, and the c[2]th cell vector is defined to give a right-handed coordinate system. In common crystallographic shorthand, $x_{c0}$ // $a{c0}$, $x{c2}$ // $a{c_2}^*$.
The new argument is set to be required, as there is no "default" option for non-orthotropic materials - different conventions are more suitable for different materials.
This PR makes the functions
utils.unitcell.cell_parameters_to_vectors()andutils.unitcell.vectors_to_cell_parameters()more flexible by adding an additional argumentframe_convention. This required argument takes a list of three integers that define the order of axes and vectors.The convention dictates that the c[0]th cell vector is colinear with the c[0]th-axis, the c[1]th cell vector is perpendicular to the c[2]th-axis, and the c[2]th cell vector is defined to give a right-handed coordinate system. In common crystallographic shorthand, $x_{c0}$ // $a{c0}$, $x{c2}$ // $a{c_2}^*$.
The new argument is set to be required, as there is no "default" option for non-orthotropic materials - different conventions are more suitable for different materials.