from the FCC gamma prime phase. One then calculates the

angles between the planes represented by any zero order

indexed spot and the FOLZ reflections listed in Table

4.1. The indexed spots in the FOLZ using the calculated

angles are shown in Figure 4.6. The indexing in the FOLZ

must be consistent with the indexing in the ZOLZ. Once

the FOLZ reflections have been indexed, the HOLZ lines in

the central spot can be indexed. The lines in the pattern

center are parallel to the lines through the FOLZ discs,

as illustrated in Figure 4.7.

 One advantage to indexing patterns from the

calculations is that the line pattern in the central spot

can be indexed directly without first indexing the

reflections in the HOLZ. An indexing of a B = [114] line

pattern is shown in Figure 4.8. To index in this way, one

first identifies the line types using Table 4.1. Next,

one finds the lowest symmetry line, if it exists, and

indexes it. This is easily done in this pattern for the

773 line. One then finds the next lowest symmetry lines

and indexes them, and so on. The sign of the vector cross

product between these lines must be consistent with the

choice of beam direction. The direction of g can be

determined from Table 1. The remaining lines are then

indexed using the calculated interplanar angles (Figure

4.6). The angles measured between HOLZ lines are slightly

different from the calculated values. In addition to

normal measurement error, these measured angles are