return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Home > Geometry > Experimental > Same bond/angle many molecules OR Comparisons > Geometry > Bonds, angles > Same bond/angle many molecules

Comparison of experiment and theory for rKK

Species with coordinate rKK
Species Name
K2 Potassium dimer
The small prefix is the number of bonds with completed calculations.
Click on an entry for a histogram of the difference distribution.
rms differences (calculated - experiment) in Å
Methods with predefined basis sets
semi-empirical PM3 1 0.756
PM6 1 1.097
composite G2 1 0.258
G3 1 0.258
G3B3 1 0.116
CBS-Q 1 0.258

rms differences (calculated - experiment) in Å
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) TZVP Def2TZVPP cc-pVDZ
hartree fock HF 1 0.442 1 0.316 1 0.319 1 0.287 1 0.299 1 0.299 1 0.299 1 0.293 1 0.293 1 0.296 1 0.296 1 0.282 1 0.254  
density functional LSDA 1 0.500 1 0.997 1 0.997 1 0.092 1 0.075 1 0.075 1 0.075 1 0.083 1 0.083 1 0.081   1 0.066    
BLYP 1 0.398 1 0.102 1 0.079 1 0.073 2 0.117 1 0.091 1 0.091 1 0.087 1 0.087 1 0.090   1 0.101    
B1B95 1 0.466   1 0.081 1 0.048 1 0.065 1 0.065 1 0.065 1 0.069 1 0.069 1 0.067   1 0.070    
B3LYP 1 0.431 1 0.083 1 0.059 1 0.051 1 0.067 1 0.067 1 0.067 1 0.064 1 0.064 1 0.066   1 0.072 1 0.120  
B3LYPultrafine         1 0.065                  
B3PW91 1 0.439 1 0.161 1 0.160 1 0.105 1 0.118 1 0.118 1 0.118 1 0.117 1 0.117 1 0.118   1 0.121    
mPW1PW91 1 0.447 1 0.163 1 0.160 1 0.107 1 0.121 1 0.121 1 0.121 1 0.120 1 0.120 1 0.120   1 0.122    
M06-2X 1 0.495 1 0.074 2 0.524 1 0.101 1 0.092 1 0.092 1 0.093 1 0.088 1 0.088 1 0.090   1 0.088    
PBEPBE 1 0.423 1 0.127 1 0.117 1 0.083 1 0.099 1 0.099 1 0.099 1 0.097 1 0.097 1 0.098   1 0.106 1 0.137  
PBEPBEultrafine         1 0.097                  
PBE1PBE 1 0.449   1 0.135 1 0.094 1 0.108 1 0.108 1 0.108 1 0.107 1 0.107 1 0.107   1 0.108    
HSEh1PBE 1 0.448 1 0.146 1 0.140 1 0.101 1 0.112 1 0.112 1 0.112 1 0.109 1 0.109 1 0.111   1 0.115    
TPSSh         1 0.186   1 0.186     1 0.187        
wB97X-D     1 0.148   1 0.101   1 0.101   1 0.098     1 0.099   1 0.101
B97D3   1 0.207     1 0.181   1 0.181   1 0.182   1 0.183      
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) TZVP Def2TZVPP cc-pVDZ
Moller Plesset perturbation MP2 1 0.421 1 0.321 1 0.299 1 0.294 2 0.168 1 0.161 1 0.158 2 0.065 1 0.014 1 0.096   1 0.279 1 0.244  
MP2=FULL 1 0.435 1 0.316 1 0.251 1 0.294 1 0.161 1 0.161 1 0.158 1 0.009 1 0.009 1 0.095   1 0.241    
MP3         1 0.152   1 0.170              
MP3=FULL         1 0.170   1 0.168              
MP4   1 0.312     1 0.160       1 0.040     1 0.262    
MP4=FULL   1 0.307     1 0.160       1 0.036          
Configuration interaction CID   1 0.314 1 0.281 1 0.294 1 0.161     1 0.093            
CISD   1 0.338 1 0.287 1 0.318 1 0.174     1 0.093            
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) TZVP Def2TZVPP cc-pVDZ
Quadratic configuration interaction QCISD   1 0.338 1 0.288 1 0.320 1 0.191 1 0.191 1 0.188 1 0.083 1 0.083 1 0.138   1 0.287    
QCISD(T)         1 0.205     1 0.090       1 0.286    
Coupled Cluster CCD   1 0.315 1 0.281 1 0.295 1 0.164 1 0.164 1 0.161 1 0.060 1 0.060 1 0.127   1 0.258    
CCSD         1 0.192     1 0.083       1 0.287    
CCSD=FULL         1 0.192             1 0.261    
CCSD(T)         1 0.206     1 0.092       1 0.286    
CCSD(T)=FULL         1 0.206             1 0.265    
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) TZVP Def2TZVPP cc-pVDZ

rms differences (calculated - experiment) in Å
Methods with effective core potentials (select basis sets)
daug-cc-pVDZ daug-cc-pVTZ daug-cc-pVQZ Sadlej_pVTZ CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF         1 0.473   1 0.473   1 0.290 1 0.290
density functional B3LYP         1 0.419   1 0.419   1 0.070 1 0.063
Moller Plesset perturbation MP2         1 0.520   1 0.520   1 0.308 1 0.286
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.