the 001 plane and the 111, the common vector is 110. For

the 001 and the 111, the vector is 110. The angle between

these two <110> vectors is 90 degrees, and hence the angle

of intersection of the two [111 planes projected onto the

[001] plane. For the 931 planes in the first order zone

of a B = [114] CBED pattern, the interplanar angles in the

[114] plane are a = 26.526, b = 54.11, 3 = 26.526, and d =

72.84. These angles are very close to those calculated

from the standard formula, as above. The sum of the

latter angles is 180.000 degrees, as it must be.