Bicapped trigonal prismatic species

Germanium has four valence electrons. Thus there are 38 valence electrons for Ge. After using 18 of them as nine lone pairs, there remain 20 electrons for the Ge9 skeleton. With n = 9, when have C = 20 = 2n + 2. Hence Gel is a closo species with a tricapped trigonal prismatic structure, as shown above. Similarly, for Ge , we have n = 9 and C = 22 = 2n + 4. So this anion has a nido structure derived from a bicapped square antiprism. This structure is also shown above. 

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