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

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

For N2+ atoms 1 and 2

For N2+ (diatomic nitrogen cation)
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 cc-pCVDZ cc-pCVTZ
Moller Plesset perturbation MP2=FULL 0.0002 0.0001 0.0001 0.0001 0.0072 0.0008 0.0008 0.0099 0.0008 0.0020 0.0006 0.0006 0.0037 0.0026 0.0007 0.0047 0.0027 0.0006 0.0016
MP3=FULL         0.0072   0.0005       0.0005 0.0005 0.0030            
MP4=FULL   0.0001     0.0008       0.0009     0.0007 0.0040   0.0007 0.0053      
B2PLYP=FULL 0.0000 0.0000 0.0000 0.0000 0.0002 0.0002 0.0002 0.0002 0.0002 0.0006 0.0002 0.0002 0.0110   0.0002 0.0012      
Quadratic configuration interaction QCISD(T)=FULL         0.0007             0.0006 0.0035   0.0006 0.0045      
Coupled Cluster CCSD=FULL         0.0007           0.0006 0.0005 0.0034 0.0024 0.0006 0.0043 0.0025    
CCSD(T)=FULL         0.0007           0.0005 0.0006 0.0034 0.0023 0.0006 0.0045 0.0024    
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 cc-pCVDZ cc-pCVTZ

n2q1.gif