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IV.A.4. (XIV.F.)

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

Isomers of CH6O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a H2OCH3OH 77 water methanol dimer   sketch of water methanol dimer
b CH3OHH2O 88 methanol water dimer   sketch of methanol water dimer
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical PM3 -263.7 a
-264.8 b
PM6 -447.2 a
1962.3 b
composite G1 NC
NC
G2MP2 NC
NC
G2 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) 6-311+G(3df,2pd) 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		  
density functional LSDA NC
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
B3LYP   NC
NC		     NC
NC		   NC
NC		         NC
NC		       NC
NC		  
B3LYPultrafine   NC
NC		     NC
NC		   NC
NC		         NC
NC		       NC
NC		  
mPW1PW91
NC		                                
PBEPBE   NC
NC		     NC
NC		   NC
NC		         NC
NC		       NC
NC		  
PBEPBEultrafine   NC
NC		     NC
NC		   NC
NC		         NC
NC		       NC
NC		  
Moller Plesset perturbation MP2FC   NC
NC		    
NC		   NC
NC		         NC
NC		       NC  
Quadratic configuration interaction QCISD                         NC
NC		        
Coupled Cluster CCD                         NC
NC		        
CCSD(T)   NC     NC                        
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF       NC NC  
density functional B1B95 NC NC
NC		        
B3LYP       NC NC  
Moller Plesset perturbation MP2FC       NC NC  
Single point energy calculations (select basis sets)
6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G* NC
NC		   NC
NC		   NC
NC
MP2FC// B3LYP/6-31G* NC
NC		 NC
NC		 NC
NC		   NC
NC
MP2FC// MP2FC/6-31G*     NC
NC		 NC
NC		 NC
NC
MP4// HF/6-31G* NC
NC		   NC
NC		   NC
NC
MP4// B3LYP/6-31G*   NC
NC		 NC
NC		   NC
NC
MP4// MP2/6-31G*     NC
NC		   NC
NC
Coupled Cluster CCSD// B3LYP/6-31G* NC
NC		        
CCSD(T)// B3LYP/6-31G* NC
NC		        
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.