An adamantane is a polycyclic hydrocarbon with a cagelike structure similar to a portion of a diamond lattice.
An adamantyl is a univalent radical derived from adamantane.
RAYMOND C. FORT has written: 'ADAMANTANE'
No, they can't. Non-polar implies that they do not have ANY electrostatic interaction or forces holding them together. Van der Waal forces are insufficient to hold molecules in a crystalline structure.