The TTD collection has been built using the following sources:
RCSR (Reticular Chemistry Structure Resource), the original data are available for free at http://rcsr.anu.edu.au/. Ref: "The Reticular Chemistry Structure Resource (RCSR) Database of, and Symbols for, Crystal Nets" O'Keeffe, M.; Peskov, M. A.; Ramsden, S. J.; Yaghi, O. M. Acc. Chem. Res. 2008, 41, 1782-1789
EPINET (Euclidean Patterns in Non-Euclidean Tilings), the original data are available for free at http://epinet.anu.edu.au/. Ref: S.J. Ramsden, V. Robins, S.T. Hyde, and S. Hungerford. “EPINET: Euclidean Patterns in Non-Euclidean Tilings.” 2005-2009. The Australian National University; S.J. Ramsden, V. Robins and S.T. Hyde, “Three-dimensional Euclidean nets from two-dimensional hyperbolic tilings: kaleidoscopic examples” Acta Cryst. (2009) A65, 81-108.
Data on the sphere packings derived by Fischer, Koch & Sowa; the data were published in a number of papers (see, e.g. and references therein Sowa, H. & Koch, E. (2005). Acta Cryst.A61, 331-342).
Crystallographic data from CSD (Cambridge Structural Database) and ICSD (Inorganic Crystal Structure Database).
Data on supernet-subnet relations (see Blatov, V. A. "Topological relations between three-dimensional periodic nets. I. Uninodal nets" (2007). Acta Cryst.A63, 329–343 and Blatov, V. A. & Proserpio D.M. "Topological relations between three-dimensional periodic nets. II. Binodal nets" (2009). Acta Cryst.A65, 202-212).