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

a  C_{2}H_{2}O  157186  Oxirene  
b  HCCOH  32038792  ethynol  
c  CH_{2}CO  463514  Ketene  0.0 
semiempirical  AM1  376.0 a 184.7 b 0.0 c 

PM3  257.9 a 101.2 b 0.0 c 

PM6  291.7 a 169.6 b 0.0 c 

MNDOd  0.0 c 

composite  G1  149.8 b 0.0 c 
G2MP2  151.2 b 0.0 c 

G2  134.8 a 151.6 b 0.0 c 

G3  139.1 a 148.2 b 0.0 c 

G3B3  235.5 a 141.1 b 0.0 c 

G3MP2  147.9 b 0.0 c 

G4  306.1 a 142.2 b 0.0 c 

CBSQ  316.5 a 141.8 b 0.0 c 

molecular mechanics  MM3  0.0 c 
STO3G  321G  321G*  631G  631G*  631G**  631+G**  6311G*  6311G**  631G(2df,p)  6311+G(3df,2p)  ccpVDZ  ccpVTZ  ccpVQZ  augccpVDZ  augccpVTZ  ccpV(T+d)Z  

hartree fock  HF  89.7 b 0.0 c 
132.5 b 0.0 c 
132.5 b 0.0 c 
132.8 b 0.0 c 
154.9 b 0.0 c 
168.6 b 0.0 c 
152.4 b 0.0 c 
156.5 b 0.0 c 
152.9 b 0.0 c 
159.9 b 0.0 c 
151.7 b 0.0 c 
151.3 b 0.0 c 
154.6 b 0.0 c 
150.9 b 0.0 c 
151.7 b 0.0 c 

density functional  LSDA  167.1 b 0.0 c 
164.2 b 0.0 c 
164.2 b 0.0 c 
163.5 b 0.0 c 
173.8 b 0.0 c 
163.3 b 0.0 c 
155.8 b 0.0 c 
172.0 b 0.0 c 
156.5 b 0.0 c 
158.6 b 0.0 c 
162.3 b 0.0 c 
151.9 b 0.0 c 
153.1 b 0.0 c 
151.9 b 0.0 c 

BLYP  167.5 b 0.0 c 
171.7 b 0.0 c 
171.7 b 0.0 c 
170.8 b 0.0 c 
182.5 b 0.0 c 
172.1 b 0.0 c 
163.9 b 0.0 c 
178.8 b 0.0 c 
164.8 b 0.0 c 
167.7 b 0.0 c 
170.0 b 0.0 c 
160.7 b 0.0 c 
0.0 c 
160.7 b 0.0 c 

B1B95  151.3 b 0.0 c 
159.2 b 0.0 c 
159.2 b 0.0 c 
158.3 b 0.0 c 
0.0 c 
163.7 b 0.0 c 
157.6 b 0.0 c 
174.4 b 0.0 c 
159.1 b 0.0 c 
160.3 b 0.0 c 
164.6 b 0.0 c 
154.7 b 0.0 c 
156.2 b 0.0 c 
154.7 b 0.0 c 

B3LYP  151.4 b 0.0 c 
162.0 b 0.0 c 
162.1 b 0.0 c 
160.8 b 0.0 c 
176.9 b 0.0 c 
166.0 b 0.0 c 
158.8 b 0.0 c 
174.3 b 0.0 c 
159.6 b 0.0 c 
0.0 c 
0.0 c 
165.4 b 0.0 c 
156.2 b 0.0 c 
157.0 b 0.0 c 
154.3 b 0.0 c 
156.2 b 0.0 c 

B3LYPultrafine  176.9 b 0.0 c 

B3PW91  155.9 b 0.0 c 
162.2 b 0.0 c 
162.2 b 0.0 c 
161.5 b 0.0 c 
177.3 b 0.0 c 
166.0 b 0.0 c 
160.1 b 0.0 c 
176.5 b 0.0 c 
161.1 b 0.0 c 
162.7 b 0.0 c 
166.9 b 0.0 c 
157.5 b 0.0 c 
0.0 c 
157.5 b 0.0 c 

mPW1PW91  151.8 b 0.0 c 
156.8 b 0.0 c 
159.9 b 0.0 c 
159.5 b 0.0 c 
173.5 b 0.0 c 
161.9 b 0.0 c 
156.1 b 0.0 c 
173.2 b 0.0 c 
160.3 b 0.0 c 
161.9 b 0.0 c 
163.3 b 0.0 c 
153.9 b 0.0 c 
0.0 c 
153.9 b 0.0 c 

PBEPBE  172.7 b 0.0 c 
172.4 b 0.0 c 
172.5 b 0.0 c 
172.3 b 0.0 c 
183.4 b 0.0 c 
172.4 b 0.0 c 
165.2 b 0.0 c 
181.6 b 0.0 c 
166.5 b 0.0 c 
168.2 b 0.0 c 
0.0 c 
171.9 b 0.0 c 
161.7 b 0.0 c 
0.0 c 
159.5 b 0.0 c 
161.7 b 0.0 c 

Moller Plesset perturbation  MP2  111.5 b 0.0 c 
146.9 b 0.0 c 
146.9 b 0.0 c 
142.3 b 0.0 c 
153.6 b 0.0 c 
166.2 b 0.0 c 
147.7 b 0.0 c 
148.1 b 0.0 c 
155.9 b 0.0 c 
b 
148.2 b 0.0 c 
142.3 b 0.0 c 

MP2=FULL  NC 
146.8 b 0.0 c 
NC 
NC 
b 
153.7 b 0.0 c 
148.6 b 0.0 c 
166.0 b 0.0 c 
147.5 b 0.0 c 
NC 
156.0 b 0.0 c 
b 
NC 

MP3  0.0 c 

MP4  NC 
NC 
171.3 b 0.0 c 
NC 
NC 

Configuration interaction  CID  NC 
160.2 b 0.0 c 
NC 

CISD  b 
162.7 b 0.0 c 

Quadratic configuration interaction  QCISD  NC 
138.2 b 0.0 c 
NC 
160.9 b 0.0 c 
153.3 b 0.0 c 
147.9 b 0.0 c 
166.4 b 0.0 c 
149.0 b 0.0 c 
NC 
157.7 b 0.0 c 
NC 
NC 

QCISD(T)  161.9 b 0.0 c 
NC 
NC 
NC 

Coupled Cluster  CCD  NC 
NC 
NC 
154.2 b 0.0 c 
NC 
NC 
NC 
NC 
NC 
151.1 b 0.0 c 
NC 
NC 

CCSD  157.2 b 0.0 c 
NC 
NC 
NC 

CCSD(T)  160.8 b 0.0 c 
0.0 c 
NC 
NC 
NC 
CEP31G  CEP31G*  CEP121G  CEP121G*  LANL2DZ  SDD  

hartree fock  HF  140.4 b 0.0 c 
182.0 b 0.0 c 
118.5 b 0.0 c 
157.7 b 0.0 c 
120.0 b 0.0 c 
119.5 b 0.0 c 
density functional  B1B95  158.1 b 0.0 c 
179.1 b 0.0 c 

B3LYP  162.8 b 0.0 c 
184.1 b 0.0 c 
148.1 b 0.0 c 
167.0 b 0.0 c 
148.6 b 0.0 c 
149.1 b 0.0 c 

Moller Plesset perturbation  MP2  146.2 b 0.0 c 
172.9 b 0.0 c 
132.3 b 0.0 c 
157.2 b 0.0 c 
130.4 b 0.0 c 
130.4 b 0.0 c 
6311+G(3df,2p)  ccpVDZ  ccpVTZ  augccpVDZ  augccpVTZ  ccpV(T+d)Z  

Moller Plesset perturbation  MP2FC// HF/631G*  149.9 b 0.0 c 
0.0 c 
148.5 b 0.0 c 
0.0 c 
0.0 c 
148.5 b 0.0 c 
MP2FC// B3LYP/631G*  143.1 b 0.0 c 
157.4 b 0.0 c 
141.9 b 0.0 c 
0.0 c 
0.0 c 
141.9 b 0.0 c 

MP2FC// MP2FC/631G*  0.0 c 
0.0 c 
56.1 b 0.0 c 
63.5 b 0.0 c 
56.1 b 0.0 c 

MP4// HF/631G*  158.0 b 0.0 c 
0.0 c 
156.1 b 0.0 c 
156.1 b 0.0 c 

MP4// B3LYP/631G*  167.5 b 0.0 c 
151.0 b 0.0 c 
151.0 b 0.0 c 

MP4// MP2/631G*  0.0 c 
65.5 b 0.0 c 
65.5 b 0.0 c 

Coupled Cluster  CCSD// HF/631G*  0.0 c 
0.0 c 
0.0 c 
0.0 c 
0.0 c 
0.0 c 
CCSD(T)// HF/631G*  0.0 c 
0.0 c 
0.0 c 
0.0 c 
0.0 c 
0.0 c 

CCSD// B3LYP/631G*  142.3 b 0.0 c 
0.0 c 
0.0 c 
0.0 c 

CCSD(T)// B3LYP/631G*  144.8 b 0.0 c 
0.0 c 
0.0 c 
0.0 c 

CCSD(T)//B3LYP/631G(2df,p)  0.0 c 
0.0 c 

CCSD// MP2FC/631G*  0.0 c 
0.0 c 
0.0 c 
61.7 b 0.0 c 
0.0 c 

CCSD(T)// MP2FC/631G*  0.0 c 
0.0 c 
0.0 c 
64.5 b 0.0 c 
0.0 c 
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.