IV.A.4. (XIV.F.) 
Relative enthalpies of isomers  Comparison of 298.15K enthalpies (kJ mol^{1})
Isomers of C_{2}H_{4}F_{2}
index  Species  CAS number  Name  Relative experimental enthalpy (kJ mol^{1})  sketch 

a  C_{2}H_{4}F_{2}  624726  1,2difluoroethane  
b  CH_{3}CHF_{2}  75376  Ethane, 1,1difluoro  0.0 
semiempirical  AM1  0.0 b 

PM6  198.0 a 0.0 b 

MNDOd  0.0 b 

composite  G1  231.0 a 0.0 b 
G2MP2  230.4 a 0.0 b 

G2  231.1 a 0.0 b 

G3  231.3 a 0.0 b 

G3B3  217.3 a 0.0 b 

G3MP2  231.1 a 0.0 b 

G4  216.0 a 0.0 b 

CBSQ  230.1 a 0.0 b 

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

hartree fock  HF  0.0 b 
240.5 a 0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

density functional  LSDA  70.2 a 0.0 b 
84.6 a 0.0 b 
84.6 a 0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

BLYP  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

B1B95  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

B3LYP  0.0 b 
230.1 a 0.0 b 
0.0 b 
0.0 b 
223.4 a 0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

B3LYPultrafine  0.0 b 

B3PW91  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

mPW1PW91  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

PBEPBE  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

STO3G  321G  321G*  631G  631G*  631G**  631+G**  6311G*  6311G**  631G(2df,p)  6311+G(3df,2p)  ccpVDZ  ccpVTZ  augccpVDZ  augccpVTZ  ccpV(T+d)Z  
Moller Plesset perturbation  MP2  0.0 b 
237.3 a 0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

MP2=FULL  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

MP3  0.0 b 

MP4  0.0 b 

Configuration interaction  CID  0.0 b 

CISD  0.0 b 

STO3G  321G  321G*  631G  631G*  631G**  631+G**  6311G*  6311G**  631G(2df,p)  6311+G(3df,2p)  ccpVDZ  ccpVTZ  augccpVDZ  augccpVTZ  ccpV(T+d)Z  
Quadratic configuration interaction  QCISD  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

STO3G  321G  321G*  631G  631G*  631G**  631+G**  6311G*  6311G**  631G(2df,p)  6311+G(3df,2p)  ccpVDZ  ccpVTZ  augccpVDZ  augccpVTZ  ccpV(T+d)Z 
CEP31G  CEP31G*  CEP121G  CEP121G*  LANL2DZ  SDD  

hartree fock  HF  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
density functional  B1B95  0.0 b 
0.0 b 

B3LYP  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

Moller Plesset perturbation  MP2  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
6311+G(3df,2p)  ccpVDZ  ccpVTZ  augccpVDZ  ccpV(T+d)Z  

Moller Plesset perturbation  MP2FC// HF/631G*  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 
MP2FC// B3LYP/631G*  0.0 b 
0.0 b 
0.0 b 
0.0 b 
0.0 b 

MP2FC// MP2FC/631G*  0.0 b 
0.0 b 
0.0 b 
0.0 b 

MP4// HF/631G*  0.0 b 
0.0 b 
0.0 b 
0.0 b 

MP4// B3LYP/631G*  0.0 b 
0.0 b 
0.0 b 

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

Coupled Cluster  CCSD// HF/631G*  0.0 b 
0.0 b 
0.0 b 

CCSD(T)// HF/631G*  0.0 b 
0.0 b 
0.0 b 

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

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

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

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

CCSD(T)// MP2FC/631G*  0.0 b 
0.0 b 
0.0 b 
0.0 b 
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (321G, 321G*, 631G, ...) 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 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.