Dear Bryan Po-Wen Chen ,

this would be um inverse problem.

In fact, if you have measured the XRD, powder or single Crystal, you have routines that will predict the Crystal probable packing, like Shape software, Materials Studio, Vesta, and some others.

Naturally, you may predict the polymorphs, and based on this information check the Crystal expected final habit.

The calculation takes into account the easy growing faces and planes, so resulting in a set of easy growth faces, extrapolated to some almost infinite distance, gives the expected habit.

By this way, even twins are possible to be predicted.

Best regards

WNM

Thanks for the information, Wagner Da Nova Mussel, Im working on Vesta now

Dear Bryan Po-Wen Chen,

Could you please clarify, do you have the experimental crystal structure of your compound (flake or needle) and you want to predict structure of the other polymorph?

Or do you want to correlate the crystal shape with the structure (e.g to which side of crystal the molecule planes are parallel)?

I also couldn't understand what is the relevance of the optimized structure to this question.

To Evgeny Bulatov, I want to correlate crystal shape with the structure.

I am actually just using quantum optimization to confirm single molecule planarity. But I dont know how they will arrange to the others (same molecules) to form a needle like crystal.

I am getting some clues in Vesta now.

Dear Bryan Po-Wen Chen,

To correlate crystal shape with the structure, you can see the unit cell axes in your crystal structure. On the other hand, unit cell measurement of single crystal affords the unit cell orientation, and from the diffractometer software you can see image of your crystal with the axes (e.g. when defining crystal shape). So you can then see which axes correspond to which crystal faces. I attached an example image made with CrysAlisPro.

If you don't measure the crystal structures yourself, perhaps your crystallographer can extract such images (crystal shape with axes) for you.

I don't know if this is of any help for you, regarding the predictions you're probably on the right track.

Best regards,

Evgeny

Thanks, Evgeny Bulatov, it's really helpful, and I have got answers from the operator.