Directions in hexagonal crystals

The Miller-Bravais index system for identifying planes and directions in hexagonal crystals is similar to the Miller index system except that it uses four axes rather than three. The advantage of the four-index system is that the symmetry is more apparent. Three of the axes, ai, a2, and a3, he in the hexagonal (basal) plane at 120° to one another and the fourth or c-axis is perpendicular to then, as shown in Figure 3.1. [Pg.21]

There is also the three-digit system for directions in hexagonal crystals. For planar indices, it uses intercepts on the ai, a2, and c axes. The indices (HKL) are related to the Miller-Bravais indices (hkil) by... [Pg.23]

As with Miller indices, directions in hexagonal crystals are sometimes specified in terms of a... [Pg.34]

As with Miller indices, to specify directions in hexagonal crystals a four-index system, u v t w ] is sometimes used. The conversion of a three-index set to a four-index set is given by the following rules ... [Pg.122]

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