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III.G.1.a.

Comparison of levels of theory for Se-S


Click on an entry for a histogram of the values.
The subscript refers to how many bonds of that type have been calculated.
average calculated bond lengths (Å)
Methods with predefined basis sets
semi-empirical AM1 2.9341
1
PM3 2.0413
2
PM6 1.8963
3
composite G2 2.0241
3
CBS-Q 2.0316
2
average calculated bond lengths (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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
hartree fock HF 2.0586
3		 2.2338
2		 2.0225
3		 2.0618
2		 2.0241
3		 2.0241
3		 2.0219
3		 2.0305
3		 2.0305
3		 2.0024
3		 2.0309
3		 2.0297
3		 2.0197
3		 2.0219
2		 2.0319
3		 2.0192
3		 2.0210
2
density functional LSDA 2.0920
3		 2.1005
3		 2.0541
3		 2.1625
3		 2.0621
3		 2.0621
3		 2.0579
3		 2.0133
2		 2.0133
2		 2.0377
2		   2.0676
3		 2.0513
3		   2.0659
3		 1.9671
1		 2.0516
2
SVWN   2.1939
3		     2.0497
1		   2.0579
3		                    
BLYP 2.1245
3		 2.1898
2		 2.0468
2		 2.2163
3		 2.1105
3		 2.1105
3		 2.1530
2		 2.1011
1		 2.1011
1		 2.0771
3		   2.1165
3		 2.1004
3		   2.1005
1		    
B1B95 2.0804
3		 2.0918
3		 2.0454
3		 2.1514
3		 2.0501
3		 2.0501
3		 2.0461
3		 2.0564
3		 2.0564
3		 2.0243
3		   2.0560
3		 2.0433
3		 2.0447
2		 2.0551
3		 2.0467
2		 2.1354
1
B3LYP 2.0981
3		 2.2108
3		 2.0695
3		 2.1796
3		 2.0776
3		 2.0776
3		 2.0738
3		 2.0834
3		 2.0834
3		 2.0479
3		 2.0822
3		 2.0832
3		 2.0683
3		 2.0712
2		 2.0819
3		 2.0667
3		 2.0693
2
B3LYPultrafine         2.0842
2		                        
B3PW91 2.0900
3		 2.1978
3		 2.0562
3		 2.1629
3		 2.0611
3		 2.0611
3		 2.0572
3		 2.0663
3		 2.0663
3		 2.0335
3		   2.0668
3		 2.0528
3		   2.0536
1		    
mPW1PW91 2.0840
3		 2.1912
3		 2.0497
3		 2.1550
3		 2.0538
3		 2.0538
3		 2.0501
3		 2.0591
3		 2.0591
3		 2.0271
3		   2.0594
3		 2.0461
3		   2.0468
1		    
M06-2X         2.0460
3		                        
PBEPBE 2.1089
3		 2.2241
3		 2.0778
3		 2.1352
2		 2.1298
2		 2.1298
2		 2.0801
3		 2.0911
3		 2.0911
3		 2.0541
3		   2.0901
3		 2.0758
3		 2.0791
2		 2.0757
1		   2.0769
2
HSEh1PBE         2.0554
3		                        
Moller Plesset perturbation MP2FC 2.1276
3		 2.3079
3		 2.0660
3		 2.2745
3		 2.0767
3		 2.0767
3		 2.0769
3		 2.0833
3		 2.0833
3		 2.0485
3		 2.0804
3		 2.0829
3		 2.0615
3		   2.0899
3		 2.0956
2		  
MP2FU 2.1275
3		 2.3089
3		 2.0651
3		 2.2756
3		 2.0736
3		 2.0736
3		 2.0737
3		 2.0811
3		 2.0811
3		 2.0349
3		   2.0818
3		 2.0568
3		        
MP3         2.0722
2		                        
MP4 2.0869
1		 2.2518
2		     2.0859
3		       2.1935
1		       2.0818
2		        
B2PLYP         2.0809
3		   2.0775
3		                    
Configuration interaction CID 2.0732
1		 2.2297
3		 2.0469
3		 2.1929
3		 2.0549
3		     2.0593
3		 2.0451
1		                
CISD 2.0855
1		 2.2346
3		 2.0498
3		 2.1970
3		 2.0578
3		     2.0625
3		 2.0479
1		                
Quadratic configuration interaction QCISD 2.0931
1		 2.2605
3		 2.0657
3		 2.2182
3		 2.0744
3		 2.0744
3		 2.0715
3		 2.1254
2		 2.1254
2		 2.0403
3		   2.0884
2		 2.0633
2		        
QCISD(T) 2.0929
1		       2.0867
3		   2.0667
1		 2.0740
1		       2.0920
3		 2.1090
2		   2.0976
3		 2.0770
2		  
Coupled Cluster CCD 2.0766
1		 2.2463
3		 2.0565
3		 2.2104
3		 2.0655
3		 2.0655
3		 2.0650
3		 2.0707
3		 2.0707
3		 2.0358
3		   2.1715
1		 2.0559
2		   2.0835
2		 2.1463
1		  
CCSD         2.0724
3		   2.0542
1		 2.0598
1		       2.0587
1		 2.0370
1		   2.0651
1		    
CCSD(T) 2.0932
1		       2.0677
1		   2.0658
1		 2.0728
1		       2.0906
3		 2.0678
3		   2.0963
3		 2.0759
2		  
CCSD(T)=FULL         2.0906
2		             2.0699
1		 2.0458
1		        
average calculated bond lengths (Å)
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 2.1520
3		   2.1517
3		   2.1853
3		 2.3439
3
density functional B3LYP 2.2021
3		   2.2019
3		   2.2271
3		 2.2075
3
Moller Plesset perturbation MP2FC 2.2451
3		   2.2894
3		   2.3219
3		 2.2664
3
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.