A Crystal with a Long Axis

This is an image plate picture from an R-AXIS data collection on an orthorhombic cell with dimensions a=10.2939(3), b=46.1361(9), c=7.0808(2) Å using Moly radiation. The image plate is 200 x 200 mm in size and the crystal to plate distance is 82 mm. This leads to a max 2q of 50° (resolution=0.83Å). The oscillation angle was 6° and the exposure time was 200 sec.

Subsequently, a second crystal was mounted on the R-AXIS with the b* axis approximately parallel to the oscillation (j) axis. A data set was collected with oscillation angles of 10° and exposures times of 5 min. Here is an image plate picture at j=-80° to -70°.

Here is an enlargement of the highlighted area in the above picture. This frame displays the 0kl level of the reciprocal cell.

Here is an image plate picture at j=20° to 30°. This frame displays the hk0 level of the reciprocal cell.

This is an enlargement of the highlighted area in the above picture.

Incidentally, this structure was an example that in crystallography, you can't always "tell a book by its cover": the sample consisted of one very large ugly crystal with "furry" micro-crystallites growing all over the outside. But it cleaved nicely, gave very pretty diffraction patterns and produced a structure determination with a least squares R factor less than 4% !

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