Experiment and theory are combined to derive crystallographic features and their consequences for polyacetylene charge-transfer complexes. A highly disordered spatial distribution of dopant is predicted and observed for lithium complexes. Periodic structures are predicted and observed for complexes involving larger dopants. The alkali metals sodium through rubidium form tetragonal channel complexes in which columns of alkali metal ions are each surrounded by four polyacetylene chains. Both first-stage and higher-stage layer complexes have been observed for iodine-doped polyacetylene