The next step is a cross-rotation function with the modified Fab structure.
The model Patterson map P1 is computed
by placing the search model into a
Å orthorhombic box, with the largest
extent of the model approximately parallel to the z-direction,
and evaluating the structure factors and
FFT of the squared amplitudes.
Note that all
crystallographic symmetry operators of the space group
have to be specified without the translational part.
X-PLOR produced the following list of highest rotation function peaks:
! index, theta1, theta2, theta3, RF-function (EPSIlon= 0.25)
1 14.843 70.000 256.306 4.7813
2 14.460 70.000 75.923 4.7643
5 20.250 77.500 92.250 4.6747
6 3.549 67.500 260.049 4.6676
8 74.504 82.500 262.163 4.6273
9 3.173 67.500 79.673 4.6189
10 20.419 80.000 270.854 4.6173
...
You may notice that the first two peaks are related by
non-crystallographic symmetry. However, this is only a
necessary but not a sufficient condition for the correctness
of the solution. In fact, this ``solution" is totally wrong.