Euhedral Filter

Only a subset of the reflection list is used in the calculations. The following filter commands can be used to create the subset.

angdistmax

With this filter parameter the angular psi-distribution can be selected. With a small value, only reflections are selected that are widely distributed in psi (recommended!). The maximum value is 2.5 (no filter). The default value = 0.6

intmin

The minimal intensity depends on the original scaling of the dataset. 200.0 is the default value.

nhklmin

It makes no sense to use reflections, which were measured only once. Therefore the redundancy must at least be 2 (which is the default).

thetamin

Reflections at low theta can be influenced by extinction. We therefore suggest a minimum theta of 12° for molybdenum radiation.

Entering the filter routine

The "filter" routine is entered by the command filter. The filter parameters mentioned above can be changed by the operator within the loop of the routine or by calling the routine later again.

Leaving the filter routine

The routine "filter" can be run as often as necessary. It can also be called again in later stages of the refinements in order to change the size of the subfile. The routine can be left with or without saving the subfile.

Example



filter picture

Steregraphic projection of the x-rays passing through the crystal. The projection is viewed along the z-axis of the cartesian system. On the left side, the top hemisphere, in the middle, the bottom hemisphere. In green, the incoming rays (forming 3 different scans). In magenta the outgoing rays. The reciprocal axes are also drawn.
Go to command overview.
Go to EUHEDRAL introduction.