Metal-rich K1-5(KI)(n)(+) (n similar to 27) clusters were produced by the supersonic cooling expansion of laser-induced KI plasma. The obtained mass spectroscopic peaks show the unique magic numbers at n = 9, 13, and 22 for K-1(KI)(n); n = 8, 12, and 21 for K-2(KI)(n); n = 8, 12, 16, and 21 for K-3(KI)(n); n 7, 9, 11, and 13 for K-4(KI)(n); and n = 12 and 21 for K-5(KI)(n). These magic numbers are fairly different from those of other reported metal-rich Na1-9(NaF)(n)(+) and Cs1-5(CsI)(n)(+) clusters. It is interesting to note that K-2.3,K-5(KI)(n)(+) clusters have the same magic numbers at n = 12 and 21 and possess structures that are closely related to the 3 x 3 x 3 and 3 x 3 x 5 cubic structures with the excess electron at the side anion vacancy or the center anion vacancy. (C) 2007 Elsevier B.V. All rights reserved.