Exercise: simplify another structure in the Hopf_ring_nets database [LAYKOM]. Build a Hopf ring net for
LAYKOM. Does the coordination of nodes in the Hopf ring net differ from GULBAR? Is the topology
of 2-fold interpenetration of the diamondoid nets the same in GULBAR and LAYKOM?
Answer: HRN for LAYKOM consist of 6-c and 10-c nodes (in ratio 1:1), while HRN for GULBAR is constructed with only 6-c nodes, so their topologies (rather as topology of interpenetration) are completely different. This shows different modes of entanglements for dia nets rings.
For more details on Hopf Ring Nets see “A topological method for classification of entanglements in crystal networks” E. V. Alexandrov, V. A. Blatov and D. M. Proserpio, Acta Cryst., A68, 2012, 484-493.