C6−C7C_{6}-C_{7}C6−C7
C5−C12\mathrm{C}_{5}-\mathrm{C}_{12}C5−C12
C5−C6C_{5}-C_{6}C5−C6
C12−C15 \mathrm{C}_{12}-\mathrm{C}_{15}C12−C15
None
