original_query: What is the purpose of generating a set of reciprocal lattice intensities in structure determination?
query: What is the purpose of generating a set of reciprocal lattice intensities in structure determination using precession electron diffraction?
answer: A three-dimensional set of intensities mapped over the reciprocal lattice, generated by collecting diffraction patterns over multiple zone axes, serves as input data for direct methods calculations in crystal structure determination.  These calculations then yield probable crystal structures.