IV.A.4. (XIV.F.) 
index  Species  CAS number  Name  Relative experimental enthalpy (kJ mol^{1})  sketch 

a  C_{12}H_{8}  208968  Acenaphthylene  0.0  
b  C_{12}H_{8}  259790  biphenylene  154.0 
semiempirical  AM1  912.8 b 

PM3  858.3 b 

PM6  807.4 b 

composite  G1  NC 
G2MP2  NC 

G2  NC 

G3  NC 

G3B3  NC 

G4  NC 

CBSQ  NC 
See section III.C.1 List or set vibrational scaling factors
to change the scale factors used here.
See section III.C.2
Calculate a vibrational scaling factor for a given set of molecules
to determine the least squares best scaling factor.