ON RATIONAL DIRECTIONS IN THE FLAT LATTICE
https://doi.org/10.22405/2226-8383-2015-16-2-273-281
Abstract
Rational and irrational rotations for the set of rational directions in the flat point lattice are considered. It is proved that in the case of rational rotations an order of noncrystallographic turn can be only 8 or 12. The set of rational 2 2 directions in the rectangular point lattice with metric quadratic form x +λ2 y and arbitrary its centering has irrational rotation if and only if the number λ2 is rational.
References
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2. Gadolin, A. B. 1867, "Displays all crystallographic systems and their units of one common origin" , Notes of the Imperial St. Petersburg Mineralogical Society., The second series. Part Four. pp. 112–200.
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Review
For citations:
Shtogrin M.I. ON RATIONAL DIRECTIONS IN THE FLAT LATTICE. Chebyshevskii Sbornik. 2015;16(2):273-281. (In Russ.) https://doi.org/10.22405/2226-8383-2015-16-2-273-281