Polycrystalline lead iodide, PbI2, was recrystallized from hot water to reproducibly obtain flat plate-like crystals, which manifested extreme preferred orientation greatly favoring the 001, 002, 003, and 004 planes. Polycrystalline samples of PbI2 were intercalated with tripropylamine, simultaneously producing a “new” intercalate 001 peak at 7.791°2θ (d=1.1347 nm) and diminishing the host PbI2 001 peak at 12.67°2θ (d=0.6980 nm). This is consistent with large increases in the c direction of the unit cell associated with inserting a guest between adjacent iodide layers of the host PbI2. Experimental powder diffraction results are compared to theoretical values calculated using CRYSTALMAKER and CRYSTALDIFFRACT software