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

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

Isomers of CH3O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CH3OO 2143580 methylperoxy radical   sketch of methylperoxy radical
b CH2OOH 9000344 CH2OOH   sketch of CH2OOH
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
composite G1 0.0 a
50.6 b
G2MP2 0.0 a
48.3 b
G2 0.0 a
49.9 b
G3 0.0 a
48.5 b
CBS-Q 0.0 a
49.0 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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 0.0 a
165.5 b 		0.0 a
90.0 b 		0.0 a
90.0 b 		0.0 a
82.8 b 		0.0 a
89.2 b 		0.0 a
76.4 b 		0.0 a
71.4 b 		0.0 a
89.5 b 		0.0 a
73.3 b 		0.0 a
76.5 b 		0.0 a
72.6 b 		0.0 a
75.9 b 		0.0 a
71.3 b 		0.0 a
71.2 b 		0.0 a
70.3 b
ROHF   0.0 a
80.1 b 		0.0 a
80.1 b 		0.0 a
73.2 b 		0.0 a
73.7 b 		0.0 a
60.8 b 		0.0 a
81.8 b 		0.0 a
73.8 b 		0.0 a
57.5 b 		    0.0 a
60.5 b 		0.0 a
52.7 b 		0.0 a
53.5 b 		0.0 a
51.1 b
density functional LSDA 0.0 a
130.3 b 		                           
BLYP 0.0 a
132.6 b 		                           
B1B95             0.0 a
78.1 b 		               
B3LYP 0.0 a
136.6 b 		      0.0 a
80.6 b 		0.0 a
69.8 b 		  0.0 a
78.7 b 		0.0 a
63.1 b 		0.0 a
67.5 b 		  0.0 a
67.1 b 		0.0 a
58.0 b 		   
B3LYPultrafine         0.0 a
80.6 b 		                   
B3PW91 0.0 a
142.2 b 		      0.0 a
80.5 b 		0.0 a
69.4 b 		0.0 a
62.2 b 		0.0 a
79.7 b 		0.0 a
63.5 b 		0.0 a
67.0 b 		  0.0 a
67.7 b 		0.0 a
58.8 b 		   
mPW1PW91 0.0 a
143.2 b 		0.0 a
76.7 b 		0.0 a
77.2 b 		  0.0 a
80.9 b 		0.0 a
69.5 b 		0.0 a
62.4 b 		0.0 a
80.3 b 		0.0 a
64.0 b 		0.0 a
67.2 b 		  0.0 a
68.0 b 		0.0 a
59.5 b 		   
PBEPBE 0.0 a
139.8 b 		                           
Moller Plesset perturbation MP2FC 0.0 a
150.9 b 		      0.0 a
52.0 b 		0.0 a
43.7 b 		0.0 a
34.6 b 		0.0 a
57.4 b 		0.0 a
38.8 b 		0.0 a
40.9 b 		0.0 a
35.5 b 		0.0 a
42.1 b 		0.0 a
30.6 b 		0.0 a
29.4 b 		 
MP2FU 0.0 a
151.1 b 		      0.0 a
52.0 b 		0.0 a
43.8 b 		0.0 a
34.8 b 		0.0 a
57.5 b 		0.0 a
38.9 b 		0.0 a
43.1 b 		  0.0 a
42.3 b 		0.0 a
31.7 b 		   
MP4         0.0 a
67.3 b 		      0.0 a
52.0 b 		           
Configuration interaction CID         0.0 a
67.1 b 		    0.0 a
71.0 b 		             
CISD         0.0 a
71.4 b 		    0.0 a
74.5 b 		             
Quadratic configuration interaction QCISD   0.0 a
84.0 b 		0.0 a
84.0 b 		  0.0 a
78.8 b 		0.0 a
70.8 b 		0.0 a
63.6 b 		0.0 a
81.1 b 		0.0 a
64.1 b 		0.0 a
66.7 b 		  0.0 a
66.2 b 		     
QCISD(T)         0.0 a
74.1 b 		                   
Coupled Cluster CCD       0.0 a
49.0 b 		0.0 a
60.7 b 		0.0 a
53.5 b 		0.0 a
46.3 b 		0.0 a
65.6 b 		0.0 a
49.6 b 		0.0 a
51.4 b 		  0.0 a
51.7 b 		     
CCSD         0.0 a
73.9 b 		                   
CCSD(T)         0.0 a
73.8 b 		                   
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 0.0 a
87.3 b 		0.0 a
87.4 b 		0.0 a
87.3 b 		0.0 a
85.9 b 		0.0 a
84.2 b 		0.0 a
84.3 b
density functional B3LYP   0.0 a
71.2 b 		  0.0 a
72.1 b 		   
Moller Plesset perturbation MP2FC   0.0 a
43.6 b 		  0.0 a
44.4 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 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.