C1 = Atom('C')
C2 = Atom('C')
C3 = Atom('C')
C4 = Atom('C')
C5 = Atom('C')
C6 = Atom('C')
C7 = Atom('C')
C8 = Atom('C')

b12 = Bond(C1,C2)
b23 = Bond(C2,C3)
b26 = Bond(C2,C6)
b34 = Bond(C3,C4)
b48 = Bond(C4,C8)
b56 = Bond(C5,C6)
b67 = Bond(C6,C7)
b78 = Bond(C7,C8)

da1 = Dihedral(C1,C2,C3,C4,180*deg)
da2 = Dihedral(C1,C2,C6,C5, 60*deg)
da3 = Dihedral(C1,C2,C6,C7,180*deg)
da4 = Dihedral(C3,C2,C6,C5,180*deg)
da5 = Dihedral(C5,C6,C7,C8,180*deg)

amber_atom_type = {C1: 'CT', C2: 'CT', C3: 'CT', C4: 'CT', C5: 'CT', C6: 'CT',
		   C7: 'CT', C8: 'CT'}

dC1a = DanglingBond(C1, Dihedral(C6,C2,C1,None, 60*deg))
dC1b = DanglingBond(C1, Dihedral(None,C1,C2,C3, 60*deg))
dC1c = DanglingBond(C1, Dihedral(C3,C2,C1,None,180*deg))
dC2a = DanglingBond(C2, Dihedral(C4,C3,C2,None,-60*deg))
dC3a = DanglingBond(C3, Dihedral(C1,C2,C3,None,-60*deg))
dC3b = DanglingBond(C3, Dihedral(C1,C2,C3,None, 60*deg))
dC4a = DanglingBond(C4, Dihedral(None,C4,C3,C2,60*deg))
dC4b = DanglingBond(C4, Dihedral(C2,C3,C4,None,180*deg))
dC5a = DanglingBond(C5, Dihedral(None,C5,C6,C7,180*deg))
dC5b = DanglingBond(C5, Dihedral(C2,C6,C5,None,-60*deg))
dC5c = DanglingBond(C5, Dihedral(C2,C6,C5,None,180*deg))
dC6a = DanglingBond(C6, Dihedral(None,C6,C2,C1,-60*deg))
dC7a = DanglingBond(C7, Dihedral(C4,C8,C7,None,180*deg))
dC7b = DanglingBond(C7, Dihedral(None,C7,C8,C4, 60*deg))
dC8a = DanglingBond(C8, Dihedral(C6,C7,C8,None,180*deg))
dC8b = DanglingBond(C8, Dihedral(None,C8,C7,C6, 60*deg))

hookup   = Hook(None, [dC1a,dC3b,dC6a])
hookup_extra = Hook(None, [dC8b])
hookdown = Hook(None, [dC2a,dC4a,dC7b])
hookdown_extra = Hook(None, [dC5b])
hookwest = Hook(None, [dC1b,dC3a])
hookeast = Hook(None, [dC5c,dC7a])
hooknorth = Hook(None, [dC1c,dC5a])
hooksouth = Hook(None, [dC4b,dC8a])