National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
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IV.A.4. (XIV.F.)

Relative enthalpies of isomers - Comparison of 0K enthalpies (kJ mol-1)

Isomers of C3H8N2O

2015 06 30 15:39
index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a NH(CH3)CONH(CH3) 96311 Urea, N,N'-dimethyl-   sketch of Urea, N,N'-dimethyl-
b N(CH3)2CONH2 598947 Urea, N,N-dimethyl-   sketch of Urea, N,N-dimethyl-
c NH2CONHC2H5 625525 Urea, ethyl-   sketch of Urea, ethyl-
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
composite G1
NC
NC
G2MP2
NC
NC
G2
NC
NC
G3
NC
NC
G3B3
NC
NC
G3MP2
NC
NC

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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
density functional LSDA
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC

NC
NC
 
NC
NC
SVWN  
NC
NC
   
NC
NC
 
NC
NC
       
NC
NC
         
BLYP
NC
NC

NC
NC
 
NC
NC
0.0 a
3.6 b
-10.9 c

NC
NC

NC
NC
 
NC
NC

NC
NC
   
NC
NC

NC
NC

NC
NC
 
NC
NC
B1B95
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC

NC
NC
 
NC
NC
B3LYP
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
B3LYPultrafine        
NC
NC
                   
NC
NC
 
B3PW91
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC

NC
NC
 
NC
NC
mPW1PW91
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC

NC
NC
 
NC
NC
M06-2X        
NC
NC
                       
PBEPBE
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC

NC
NC
 
NC
NC
PBEPBEultrafine        
NC
NC
                       
PBE1PBE        
NC
NC
                       
HSEh1PBE  
NC
NC
   
NC
NC
 
NC
NC
           
NC
NC
     
TPSSh        
NC
NC
 
NC
NC
   
NC
NC
     
NC
NC
     
wB97X-D    
NC
NC
 
NC
NC
     
NC
NC
       
NC
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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC
       
MP2=FULL        
NC
NC
   
NC
NC

NC
NC
               
MP3        
NC
NC
                       
MP3=FULL        
NC
NC
 
NC
NC
                   
B2PLYP        
NC
NC
               
NC
NC
     
B2PLYP=FULLultrafine        
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) TZVP cc-pVDZ cc-pVTZ 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
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
density functional B1B95
NC
NC

NC
NC
       
B3LYP
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
Moller Plesset perturbation MP2
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

Single point energy calculations (select basis sets)
cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G*
NC
NC

NC
NC
   
NC
NC
MP2FC// B3LYP/6-31G*
NC
NC
       
MP2FC// MP2FC/6-31G*    
NC
NC

NC
NC
 
Coupled Cluster CCSD// MP2FC/6-31G*      
NC
NC
 
CCSD(T)// MP2FC/6-31G*      
NC
NC
 
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 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.