Editing Baddeleyite (section)

==Structure==
There has been some dispute in the structure of baddeleyite.  Originally, the mineral was assigned to the 8-fold coordination by Naray Szabo. This structure was ruled out due to the inaccuracy of the data used to establish it.

Baddeleyite has the group symmetry P2<sub>1</sub>/c with four ZrO<sub>2</sub> in the [[unit cell]]. It has unit cell dimensions of:
a = 5.169  b = 5.232  c = 5.341 [[Angstrom|Å]] (all ± 0.008 Å), β =  99˚15ˊ ± 10ˊ.

The coordination number for ZrO<sub>2</sub> has been found to be 7. The mineral has two types of separations. The first being the seven shortest Zr-O, ranging from 2.04 to 2.26 Å, and the second Zr-O separation is 3.77 Å.  Because of this, the coordination of baddeleyite was determined to be sevenfold. Baddeleyite's structure is a combination of tetrahedrally coordinated oxide ions parallel to (100) with triangular coordinated oxide ions. This explains baddeleyite's tendency to twin along the (100) planes. It has been observed that baddeleyite without twinning is extremely rare.<ref name= McCullough >{{cite journal|author1=McCullough, J. D.  |author2=Trueblood, K. N. |name-list-style=amp |doi=10.1107/S0365110X59001530|title=The crystal structure of baddeleyite (monoclinic ZrO2)|year=1959|journal=Acta Crystallographica|volume=12|issue=7|pages=507|bibcode=1959AcCry..12..507M }}</ref>