One day I faced the following problem: to fit the diffraction pattern knowing initial lattice parameters and crystal system, however, exact space group was unknown.
Чтобы построить полную теорию, фактов всегда достаточно, не хватает только фантазии.
[There are always enough facts to build a complete theory, only fantasy is lacking.
Last evening had a nice chat with a friend of mine from the Materials Science Department. At a certain point we came to a discussion about the crystal structure and ways to represent it. As my counterpart was pointing out that it’s enough to give chemical composition and a space group to define the crystal structure, he stated that Strukturbericht notation is superfluous and useless.
We had a long and interesting discussion, which I omit here. However, we came to an agreement that at least in the following phrase, using the Strukturbericht notation is good, as it gives the shortest and clearest explanation of what is going on:
“Ni2MnAl exhibits structural transitions between the L21↔ B2 ↔ A2 phases at 990 K and 1220 K, respectively.”