CrystalMaker includes a Transform > Unit Cell > Generate Transformation command, designed to let you easily transform lattices, such as converting an hexagonal lattice to a rhombohedral lattice (or vice versa).
To convert from an hexagonal cell to a rhombohedral cell:
Choose: Transform > Unit Cell > General Transformation to display the General Transformation sheet.
Using the Examples popup menu, specify Primitive Cell.
Click the Apply Transformation button to replot your structure with a Primitive - and rhombohedral - unit cell.
To convert from a rhombohedral cell to an hexagonal cell:
Choose: Transform > Unit Cell > General Transformation to display the General Transformation sheet.
Using the Examples popup menu, specify Rhombohedral Cell.
This may appear a little confusing, as you're going from a 'rhombohedral'-shaped unit cell to an 'hexagonal'-shaped cell, not the other way round! However, the term "Rhombohedral" here refers to the lattice type, R, which uses hexagonal axes, and three lattice points per unit cell.
Click the Apply Transformation button to replot your structure with an hexagonal "R" lattice.
Tip: When transforming unit cells in this way, CrystalMaker prints the transformation matrix - and the inverse matrix (necessary to undo the operation) - in the Window Log.
See Also