5-15
Z-axis projection showing electric (Dauphiné)
twins separated by a twin wall of one unit cell
thickness.  The numbers in the atoms are
atom heights expressed in units of percent of
a unit cell height.  The atom shifts during
twinning involve motions of <0.03 nm.
33
45
67
21
21
00
79
67
45
12
21
45
67
33
88
55
79
00
88
79
00
88
Silicon
Oxygen
Domain
        Wall
Quartz Lattice and Twinning
T. L. Anderson, R. E. Newnham and L. E. Cross, "Coercive Stress for Ferrobielastic Twinning in Quartz," Proc. 31st Annual Symposium on Frequency Control, pp. 171-177, 1977, AD-A088221.  Proc. copies available from NTIS.