Barium oxide coordination number

The structural basis for the instability may be found in the inability of Ba " " to adjust to low coordination numbers. Barium ions in naturally occurring minerals and oxides have coordination numbers ranging from 6 to 10 (21). Some Baz+ ions in hydrated Bag-A have a coordination number of 6, which, upon dehydration, would be reduced to 3, the partially Baz+-exchanged structures indicate, if dehydrated Bag-A were to form. 

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