Hmm, I guess, that the slit/point/1D detectors and diffractometer geometry that are commonly used in powder diffractometers are not very suitable for such measurements...

Do you have a large 2D detector and appropriate soft on it?

if no, use back reflection Laue or a single crystal diffractometer. For such large crystal on a single crystal diffractometer(which is easily available) it could be a little tricky. you will ned to fix your crystal in special holder using something like bees wax or gummy... :) then you will need to check the collision of your big crystal with LT nozzle and primary beam trap... Probably you will need to move or even remove it! Remember about safety, if you will need to remove beam trap, better ask experienced crystallographer to assist you at least first time!!!! Because the primary beam could be dangerous not only for human, but for detector too!

If your big crystal contains strong absorber(like Br,I, Te, Pb, Bi, Hg, Ag, etc) there is usually no diffraction(due to strong absorption), and all (or almost all) power of primary/diffracted beam/reflections will be absorbed inside your big crystal!!! So, on a single crystal diffractomter you would need to use a specially manually written list of runs to scan diffraction (better from the largest face) of the crystal as if from mirror (because the crystal is non transparent to transmission).

Then, having enough reflections you will index it. May be not the first time, and not even the second... because area for reflecting is restricted. As a result you will get cell parameters and orientation matrix which can be used in a software for indexing faces like FACE INDEX... that's it.

Dear Eduard Rusanov thank you for your suggestions.

I have an EIGER 2D detector that can be used on the powder diffractometer.

Mounting the crystal on a glass capillary shouldn’t be that difficult using wax as you suggested, but I wonder if manually editing the scans on my SC machine (D8 Venture) takes longer than accurately orienting each crystal face on the powder diffractometer using a standard Bragg-Brentano geometry with a motorized stage to set the appropriate height

Dear Enrico,

2D Eiger is good, and if you think it's easier to orient each face of a plate on a PD, instead just onlyone and only roughly on the specialized SCD,

+ on the PD installation other detector, collimator... +Soft...

so, why not? :)

1) a tiny glass capillary may not be the best idea. I use for indexing the faces of a large xtals standard holder (with Nd magnet)without needle. Crystal glued with sticky polymeric composition. ( take a look attached picture.) You can easily adjust it,any time, because composite is soft.

If your sample is transparent for xray(no strong absorption), it is much easy, because you can use diffractometer in normal mode with standard preset of runs for cell determination with standard methods, so the next point 2 is not necessary.

2) Orienting only one crystal face to Bruker is not so difficult, usually 1 good omega-run with 5-10 images after an omega scan (step = 1 degree) is enough for indexing+ you can oscillate other runs based on a 1st in a bit other directions with a bit modified angles. For first time you can use standard runs (maybe in one of them the crystal will be close to the optimal orientation) and then you will see (thanks to a big xtal!!!)how to change the angles in the run manually... (usually omega and Phi only) o, it takes not so long time. After that Index/Face Edit will takes 1 min or so...

with best regards

Dear Eduard Rusanov

Thanks for your reply and sharing your tricks :)

Unfortunately, the sample is quite a strong absorber (perovskites) but I will definitely give it a go with the SCD.

Best wishes

:( 4 mm of perovskite with Pb, Cs, I, Br... is to much even for Mo radiation!!!... and your Perovskite probably for hard xray/gamma detection? on a pict you can also see the perovskite crystal like yours. :) The absorption is extremally high!

With best regards