return to home page Computational Chemistry Comparison and Benchmark DataBase Release 20 (August 2019) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Comparisons > Geometry > Bonds, angles > Core correlation - bond length

Bond Length differences between FULL (all electrons correlated) and FROZEN core

Such as MP2=Frozen and MP2=Full
17 10 27 16 27

For Mg2 atoms 1 and 2

For Mg2 (Magnesium diatomic)
Bond length differences (full - frozen) in Å. Mouse over a difference for the bond length with full correlation.
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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
Moller Plesset perturbation MP2=FULL 0.0261 0.0019 0.2245 -2.6514 -1.7097 -1.8233 1.8921 -1.6315 0.0790 -1.2237 0.0332 1.6748 1.1745 0.0184 1.5090 0.2311 0.0208
MP3=FULL         1.5618   -1.5170       0.0506 0.0112 0.2548        
MP4=FULL   0.0240     -1.4852       0.0644     0.0120 0.2514   0.0295 0.2984  
Coupled Cluster CCSD=FULL         -2.5696           0.0482 0.1140 0.5663 0.3050 0.1380 0.6219 0.3335
CCSD(T)=FULL         0.1042           0.0493 0.0604   0.1549 0.0614 0.3589 0.1795
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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ

mg2q1.gif