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

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

Isomers of C8H8

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C6H5CHCH2 100425 Styrene 0.0 sketch of Styrene
b C8H8 629209 cyclooctatetraene 150.7 sketch of cyclooctatetraene
c C8H8 277101 cubane 475.3 sketch of cubane
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 0.0 a
103.8 b
470.8 c
PM3 0.0 a
113.2 b
326.2 c
PM6 0.0 a
85.7 b
286.5 c
MNDOd 0.0 a
composite G1 0.0 a
152.2 b
476.6 c
G2MP2 0.0 a
150.3 b
456.6 c
G2 0.0 a
150.7 b
456.3 c
G3 0.0 a
152.3 b
469.7 c
G3B3 0.0 a
148.5 b
463.5 c
G3MP2 0.0 a
150.7 b
474.8 c
molecular mechanics MM3 0.0 a
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 aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF 0.0 a
197.0 b
151.5 c 		0.0 a
170.1 b
460.7 c 		0.0 a
170.1 b
460.7 c 		0.0 a
174.0 b
588.5 c 		0.0 a
161.2 b
501.4 c 		0.0 a
161.4 b
502.5 c 		0.0 a
521.1 c 		0.0 a
156.0 b
513.3 c 		0.0 a
157.0 b
515.6 c 		0.0 a
155.0 b
501.7 c 		0.0 a
155.7 b
526.0 c 		0.0 a
158.4 b
511.3 c 		0.0 a
157.2 b
530.7 c 		0.0 a
156.0 b
508.7 c 		0.0 a
156.6 b
532.2 c 		0.0 a
157.2 b
530.7 c
density functional LSDA 0.0 a
205.9 b
136.1 c 		0.0 a
163.1 b
320.3 c 		0.0 a
163.1 b
320.3 c 		0.0 a
172.4 b
435.3 c 		0.0 a
169.4 b
366.9 c 		0.0 a
169.0 b
367.2 c 		0.0 a
163.5 b
378.5 c 		0.0 a
158.3 b
380.5 c 		0.0 a
159.3 b
381.9 c 		0.0 a
167.1 b
361.3 c 		  0.0 a
164.2 b
357.9 c 		0.0 a
162.2 b
396.8 c 		0.0 a
160.6 b
370.4 c 		  0.0 a
162.2 b
396.8 c
BLYP 0.0 a
190.4 b
259.0 c 		0.0 a
162.6 b
438.3 c 		0.0 a
162.6 b
438.3 c 		0.0 a
167.5 b
568.8 c 		0.0 a
164.0 b
510.2 c 		0.0 a
163.6 b
509.9 c 		0.0 a
159.4 b
524.9 c 		0.0 a
155.6 b
527.8 c 		0.0 a
529.0 c 		0.0 a
510.4 c 		  0.0 a
160.7 b
505.5 c 		0.0 a
157.6 b
546.8 c 		0.0 a
156.7 b
517.4 c 		  0.0 a
157.6 b
546.8 c
B1B95 0.0 a
203.5 b
158.0 c 		0.0 a
165.2 b
333.3 c 		0.0 a
165.2 b
333.3 c 		0.0 a
173.6 b
460.0 c 		0.0 a
169.8 b
395.6 c 		0.0 a
169.4 b
398.4 c 		0.0 a
165.7 b
410.6 c 		0.0 a
162.6 b
408.6 c 		0.0 a
163.4 b
409.7 c 		0.0 a
169.2 b
393.5 c 		  0.0 a
166.1 b
393.1 c 		0.0 a
167.6 b
418.1 c 		0.0 a
164.9 b
393.7 c 		  0.0 a
167.6 b
418.1 c
B3LYP 0.0 a
196.9 b
221.0 c 		0.0 a
166.7 b
423.8 c 		0.0 a
166.7 b
423.8 c 		0.0 a
172.2 b
552.6 c 		0.0 a
167.8 b
488.4 c 		0.0 a
167.5 b
488.5 c 		0.0 a
163.6 b
503.8 c 		0.0 a
160.0 b
506.6 c 		0.0 a
160.8 b
508.3 c 		0.0 a
159.6 b
491.0 c 		0.0 a
522.3 c 		0.0 a
164.6 b
486.9 c 		0.0 a
162.3 b
525.7 c 		0.0 a
161.5 b
499.0 c 		  0.0 a
162.3 b
525.7 c
B3LYPultrafine         0.0 a
488.4 c 		                     
B3PW91 0.0 a
202.6 b
179.7 c 		0.0 a
167.5 b
358.3 c 		0.0 a
167.5 b
358.3 c 		0.0 a
173.8 b
488.9 c 		0.0 a
169.4 b
425.3 c 		0.0 a
169.2 b
425.4 c 		0.0 a
165.5 b
437.1 c 		0.0 a
162.0 b
438.5 c 		0.0 a
163.0 b
439.9 c 		0.0 a
425.5 c 		  0.0 a
165.6 b
421.6 c 		0.0 a
165.2 b
454.1 c 		0.0 a
163.7 b
431.1 c 		  0.0 a
165.2 b
454.1 c
mPW1PW91 0.0 a
204.2 b
163.8 c 		0.0 a
167.5 b
345.0 c 		0.0 a
167.7 b
338.7 c 		0.0 a
180.9 b
477.3 c 		0.0 a
169.7 b
412.4 c 		0.0 a
169.5 b
412.5 c 		0.0 a
165.7 b
425.1 c 		0.0 a
168.7 b
431.6 c 		0.0 a
163.5 b
427.1 c 		0.0 a
412.8 c 		  0.0 a
166.0 b
409.5 c 		0.0 a
172.1 b
447.6 c 		0.0 a
418.7 c 		  0.0 a
172.1 b
447.6 c
PBEPBE 0.0 a
198.0 b
197.6 c 		0.0 a
163.2 b
345.2 c 		0.0 a
163.1 b
345.1 c 		0.0 a
169.1 b
481.5 c 		0.0 a
165.7 b
421.6 c 		0.0 a
165.3 b
421.4 c 		0.0 a
160.8 b
433.6 c 		0.0 a
157.7 b
432.6 c 		0.0 a
158.5 b
433.6 c 		0.0 a
158.3 b
418.2 c 		0.0 a
158.8 b
444.2 c 		0.0 a
161.8 b
414.2 c 		0.0 a
160.8 b
447.7 c 		0.0 a
425.6 c 		  0.0 a
160.8 b
447.7 c
PBEPBEultrafine         0.0 a
421.6 c 		                     
Moller Plesset perturbation MP2FC 0.0 a
187.5 b
271.6 c 		0.0 a
158.9 b
467.7 c 		0.0 a
158.9 b
467.7 c 		0.0 a
161.6 b
586.2 c 		0.0 a
173.8 b
465.4 c 		0.0 a
174.1 b
464.5 c 		0.0 a
168.3 b
486.7 c 		0.0 a
168.0 b
455.7 c 		0.0 a
168.7 b
452.1 c 		0.0 a
426.6 c 		  0.0 a
172.8 b
452.6 c
  b 		   
  b
MP2FU   0.0 a
159.1 b
466.6 c
  b
  c 		0.0 a
161.8 b
584.4 c 		0.0 a
174.4 b
458.6 c 		0.0 a
174.8 b
457.2 c 		0.0 a
169.0 b
479.5 c 		0.0 a
168.4 b
451.4 c 		0.0 a
169.2 b
447.2 c 		    0.0 a
173.3 b
451.9 c
  c 		   
  c
MP3         0.0 a
453.6 c 		                     
Configuration interaction CID  
NC		    
  b
  c 		                     
CISD  
NC		    
  b
  c 		                     
Quadratic configuration interaction QCISD   0.0 a
439.0 c
NC
NC
  c
  c 		 
NC
NC		    
NC		        
Coupled Cluster CCD  
NC
NC
NC
NC
NC		  
NC		      
NC		        
CCSD(T)        
NC		                      
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 0.0 a
180.7 b
528.7 c 		0.0 a
167.3 b
422.4 c 		0.0 a
173.0 b
547.3 c 		0.0 a
158.2 b
478.9 c 		0.0 a
176.3 b
576.9 c 		0.0 a
176.4 b
573.9 c
density functional B1B95 0.0 a
182.4 b
377.0 c 		0.0 a
177.5 b
299.7 c 		       
B3LYP 0.0 a
179.6 b
473.1 c 		0.0 a
174.5 b
411.8 c 		0.0 a
171.4 b
507.9 c 		0.0 a
165.2 b
464.7 c 		0.0 a
175.8 b
516.9 c 		0.0 a
175.7 b
516.9 c
Moller Plesset perturbation MP2FC 0.0 a
169.4 b
520.2 c 		0.0 a
178.0 b
378.2 c 		0.0 a
150.3 b
530.5 c 		0.0 a
164.1 b
425.4 c 		0.0 a
160.0 b
555.6 c 		0.0 a
160.0 b
553.7 c
Single point energy calculations (select basis sets)
aug-cc-pVDZ
Moller Plesset perturbation MP2FC// MP2FC/6-31G* 0.0 a
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.