return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Comparisons > Energy > Similar molecules > Isomers OR FAQ Help > List > Similar molecules > Isomers

Relative enthalpies of isomers - Comparison of 298.15K enthalpies (kJ mol-1)

Isomers of C2H2O

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C2H2O 157186 Oxirene   sketch of Oxirene
b CH2CO 463514 Ketene 0.0 sketch of Ketene
c HCCOH 32038792 ethynol 89.3 sketch of ethynol
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 376.0 a
0.0 b
184.7 c
PM3 299.0 a
PM6 291.7 a
0.0 b
169.6 c
MNDOd
0.0 b
composite G1
0.0 b
146.7 c
G2MP2
0.0 b
148.1 c
G2 314.4 a
0.0 b
148.5 c
G3 318.8 a
0.0 b
145.1 c
G3B3 235.5 a
0.0 b
141.1 c
G3MP2
0.0 b
144.8 c
G4 306.1 a
0.0 b
142.2 c
CBS-Q 316.5 a
0.0 b
141.8 c
molecular mechanics MM3
0.0 b

Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
0.0 b
89.7 c

0.0 b
132.5 c

0.0 b
132.5 c

0.0 b
132.8 c
 
0.0 b
154.9 c
 
0.0 b
168.6 c

0.0 b
152.4 c

0.0 b
156.5 c

0.0 b
152.9 c

0.0 b
159.9 c

0.0 b
151.7 c

0.0 b
151.3 c

0.0 b
154.6 c

0.0 b
150.9 c

0.0 b
151.7 c
density functional LSDA
0.0 b
167.1 c

0.0 b
164.2 c

0.0 b
164.2 c

0.0 b
163.5 c

0.0 b
173.8 c

0.0 b
163.3 c

0.0 b
155.8 c

0.0 b
172.0 c

0.0 b
156.5 c

0.0 b
158.6 c
 
0.0 b
162.3 c

0.0 b
151.9 c
 
0.0 b
153.1 c
 
0.0 b
151.9 c
BLYP
0.0 b
167.5 c

0.0 b
171.7 c

0.0 b
171.7 c

0.0 b
170.8 c
 
0.0 b
172.1 c

0.0 b
163.9 c

0.0 b
178.8 c

0.0 b
164.8 c

0.0 b
167.7 c
 
0.0 b
170.0 c

0.0 b
160.7 c
 
0.0 b
 
0.0 b
160.7 c
B1B95
0.0 b
151.3 c

0.0 b
159.2 c

0.0 b
159.2 c

0.0 b
158.3 c

0.0 b

0.0 b
163.7 c

0.0 b
157.6 c

0.0 b
174.4 c

0.0 b
159.1 c

0.0 b
160.3 c
 
0.0 b
164.6 c

0.0 b
154.7 c
 
0.0 b
156.2 c
 
0.0 b
154.7 c
B3LYP
0.0 b
151.4 c

0.0 b
162.0 c

0.0 b
162.1 c

0.0 b
160.8 c

0.0 b
176.9 c

0.0 b
166.0 c

0.0 b
158.8 c

0.0 b
174.3 c

0.0 b
159.6 c

0.0 b

0.0 b

0.0 b
165.4 c

0.0 b
156.2 c
 
0.0 b
157.0 c

0.0 b
154.3 c

0.0 b
156.2 c
B3LYPultrafine        
0.0 b
176.9 c
                       
B3PW91
0.0 b
155.9 c

0.0 b
162.2 c

0.0 b
162.2 c

0.0 b
161.5 c

0.0 b
177.3 c

0.0 b
166.0 c

0.0 b
160.1 c

0.0 b
176.5 c

0.0 b
161.1 c

0.0 b
162.7 c
 
0.0 b
166.9 c

0.0 b
157.5 c
 
0.0 b
 
0.0 b
157.5 c
mPW1PW91
0.0 b
151.8 c

0.0 b
156.8 c

0.0 b
159.9 c

0.0 b
159.5 c

0.0 b
173.5 c

0.0 b
161.9 c

0.0 b
156.1 c

0.0 b
173.2 c

0.0 b
160.3 c

0.0 b
161.9 c
 
0.0 b
163.3 c

0.0 b
153.9 c
 
0.0 b
 
0.0 b
153.9 c
PBEPBE
0.0 b
172.7 c

0.0 b
172.4 c

0.0 b
172.5 c

0.0 b
172.3 c

0.0 b
183.4 c

0.0 b
172.4 c

0.0 b
165.2 c

0.0 b
181.6 c

0.0 b
166.5 c

0.0 b
168.2 c

0.0 b

0.0 b
171.9 c

0.0 b
161.7 c
 
0.0 b

0.0 b
159.5 c

0.0 b
161.7 c
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2
0.0 b
111.5 c

0.0 b
146.9 c

0.0 b
146.9 c

0.0 b
142.3 c
 
0.0 b
153.6 c
   
0.0 b
147.7 c

  c
 
0.0 b
155.9 c

  c
 
0.0 b
148.2 c
 
0.0 b
142.3 c
MP2=FULL
NC

0.0 b
146.8 c

NC

NC

  c

0.0 b
153.7 c

0.0 b
148.6 c

0.0 b
166.0 c

0.0 b
147.5 c

  c
 
0.0 b
156.0 c

  c
     
NC
MP3        
0.0 b
                       
MP4
NC

NC
   
0.0 b
171.3 c
     
NC

NC
             
Configuration interaction CID  
NC
   
0.0 b
160.2 c
       
NC
             
CISD  
  c
   
0.0 b
162.7 c
                       
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD
NC

0.0 b
138.2 c
 
NC

  c

0.0 b
153.3 c

0.0 b
147.9 c

0.0 b
166.4 c

0.0 b
149.0 c

  c
 
0.0 b
157.7 c

  c
     
NC
QCISD(T)        
0.0 b
161.9 c
     
NC
     
NC
     
NC
Coupled Cluster CCD
NC

NC
 
NC

  c

NC

NC

NC

NC

NC
 
0.0 b
151.1 c

NC
     
NC
CCSD        
  c
     
NC
     
  c
     
NC
CCSD(T)        
0.0 b
160.8 c

0.0 b
   
NC
     
NC
     
NC
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF
0.0 b
140.4 c

0.0 b
182.0 c

0.0 b
118.5 c

0.0 b
157.7 c

0.0 b
120.0 c

0.0 b
119.5 c
density functional B1B95
0.0 b
158.1 c

0.0 b
179.1 c
       
B3LYP
0.0 b
162.8 c

0.0 b
184.1 c

0.0 b
148.1 c

0.0 b
167.0 c

0.0 b
148.6 c

0.0 b
149.1 c
Moller Plesset perturbation MP2
0.0 b
146.2 c

0.0 b
172.9 c

0.0 b
132.3 c

0.0 b
157.2 c

0.0 b
130.4 c

0.0 b
130.4 c

Single point energy calculations (select basis sets)
6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G*
0.0 b
146.8 c

0.0 b

0.0 b
145.3 c

0.0 b

0.0 b

0.0 b
145.3 c
MP2FC// B3LYP/6-31G*
0.0 b
143.1 c

0.0 b
157.4 c

0.0 b
141.9 c

0.0 b

0.0 b

0.0 b
141.9 c
MP2FC// MP2FC/6-31G*
0.0 b

0.0 b

0.0 b
140.1 c

0.0 b
147.6 c
 
0.0 b
140.1 c
MP4// HF/6-31G*
0.0 b
154.9 c

0.0 b

0.0 b
153.0 c
   
0.0 b
153.0 c
MP4// B3LYP/6-31G*  
0.0 b
167.5 c

0.0 b
151.0 c
   
0.0 b
151.0 c
MP4// MP2/6-31G*
0.0 b
 
0.0 b
149.6 c
   
0.0 b
149.6 c
Coupled Cluster CCSD// HF/6-31G*
0.0 b

0.0 b

0.0 b

0.0 b

0.0 b

0.0 b
CCSD(T)// HF/6-31G*
0.0 b

0.0 b

0.0 b

0.0 b

0.0 b

0.0 b
CCSD// B3LYP/6-31G*
0.0 b
142.3 c

0.0 b

0.0 b
   
0.0 b
CCSD(T)// B3LYP/6-31G*
0.0 b
144.8 c

0.0 b

0.0 b
   
0.0 b
CCSD(T)//B3LYP/6-31G(2df,p)    
0.0 b
   
0.0 b
CCSD// MP2FC/6-31G*
0.0 b

0.0 b

0.0 b

0.0 b
145.7 c
 
0.0 b
CCSD(T)// MP2FC/6-31G*
0.0 b

0.0 b

0.0 b

0.0 b
148.5 c
 
0.0 b
NC = not calculated
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.
gaw refers to the group additivity method implemeted in the NIST Chemistry Webbook.
See section Calculated; Vibrations; Scale Factors; Scale factors to list vibrational scaling factors.
See section Calculated; Vibrations; Scale Factors; Calculate a scale factor to calculate a vibrational scaling factor for a given set of molecules.