An illustrative example: There are two types of Zintl ions in KSi; 2x  (pseudo P,
or according to Wades rules, 12 = 2n + 4 skeletal-electrons corresponding to a nido'-form of a trigonal-bipyramid) and 1x
 (according to Wades rules, 22 = 2n + 4 skeletal-electrons corresponding to a nido'-form of a bicapped square antiprism)
Examples from Müller's 1973 review paper with known structures are listed in the table below.