CYCLACENES ARE A CLASS OF FUSED BENZENOID HYDROCARBONS WITH A SIMPLE CONCEPTUAL FRAMEWORK FOR UNDERSTANDING THE STRUCTURES AND PROPERTIES OF CARBON NANOTUBES (CNTS) AND FULLERENE SYSTEMS. [1] A CYCLACENE STRUCTURE HAS TWO TYPES OF CONSTITUENTS INCLUDING AN ARE NOID BELT-COMPOSED OF FUSED BENZENOID RINGS-DISPLAYING TWO RATHER LARGE ANNULENIC PERIPHERAL RINGS THAT ARE MADE OF TRANSOID DOUBLE BONDS WITH EITHER 4K OR 4K+2 ELECTRONS (FIG.1). SIMILAR TO THE REPORTED OPEN-SHELL ZIGZAG [6]N CYCLACENES (N=6-10), THEIR ANALOGUES WHICH CONTAIN ALTERNATING GE-C BONDS, APPEAR WITH OPEN-SHELL SINGLET ELECTRONIC GROUND STATES, AT UNRESTRICTED BROKEN SPIN-SYMMETRY AT dft (N=THE NUMBER OF FUSED BENZENOID RINGS). IN ALL TEN CASES, MACROCYCLES MINIMA ARE OBTAINED WHICH ARE PUT TOGETHER THROUGH LINEAR ANNELATION OF CONJUGATED RINGS TO HOOP SHAPES.