KDP and DKDP crystals of various habits were grown at rates of 10-20 mm/day to linear sizes near 90 cm. The ratio of dimensions along the crystallographic axes was controlled by two methods: (1) creation of special dislocation structures during the seed regeneration process and (2) change in the orientation of the seed. The methods to control crystal habit and dislocation structure during subsequent growth are described. (C) 2002 Elsevier Science B.V. All rights reserved.