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III.G.1.a.

Comparison of levels of theory for N-P


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 1.4005
2
PM3 1.4354
3
PM6 1.4984
3
composite G2 1.5364
3
G3 1.5364
3
G3B3 1.5184
3
CBS-Q 1.5364
3
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) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z
hartree fock HF 1.5676
3		 1.5983
3		 1.5577
3		 1.5983
3		 1.5013
2		 1.5364
3		 1.5309
3		 1.5289
3		 1.5255
2		 1.5181
3		 1.4463
1		 1.5441
3		 1.5527
3		 1.5232
3		 1.5128
3		 1.5492
3		 1.5202
3		 1.5104
3		 1.4480
1
density functional LSDA 1.5569
3		 1.5459
3		 1.5295
3		 1.5867
3		 1.5209
3		 1.5209
3		 1.5143
3		 1.5126
3		 1.5126
3		 1.5100
3		     1.5304
3		 1.5101
3		 1.5114
2		 1.5235
3		 1.5118
2		 1.5044
2		  
SVWN   1.5857
3		     1.5209
3		   1.5144
3		                        
BLYP 1.5724
3		 1.6037
3		 1.5476
3		 1.6067
3		 1.5387
3		 1.5387
3		 1.5406
2		 1.5315
3		 1.5315
3		 1.5274
3		     1.5477
3		 1.5277
3		   1.5213
1		      
B1B95 1.5801
3		 1.5363
3		 1.5202
3		 1.5778
3		 1.5105
3		 1.5113
3		 1.5059
3		 1.5053
3		 1.5053
3		 1.5024
3		     1.5206
3		 1.5029
3		 1.5061
2		 1.5150
3		 1.5369
1		 1.5000
2		  
B3LYP 1.5883
3		 1.5840
3		 1.5271
3		 1.5859
3		 1.5184
3		 1.5184
3		 1.5129
3		 1.5118
3		 1.5231
2		 1.5081
3		 1.4812
1		 1.5184
3		 1.5273
3		 1.5090
3		 1.5022
3		 1.5220
3		 1.5047
3		 1.4982
3		 1.4826
1
B3LYPultrafine         1.5184
3		                            
B3PW91 1.6211
2		 1.5826
3		 1.5253
3		 1.5832
3		 1.5156
3		 1.5156
3		 1.5100
3		 1.5091
3		 1.5200
2		 1.5062
3		     1.5250
3		 1.5071
3		   1.5006
1		      
mPW1PW91 1.6167
2		 1.5792
3		 1.5334
2		 1.5800
3		 1.5117
3		 1.5117
3		 1.5064
3		 1.5055
3		 1.5055
3		 1.5025
3		     1.5211
3		 1.5036
3		   1.4968
1		      
M06-2X         1.5041
3		                            
PBEPBE 1.5823
2		 1.6007
3		 1.5560
2		 1.6176
2		 1.5344
3		 1.5344
3		 1.5274
3		 1.5274
3		 1.5274
3		 1.5243
3		 1.4980
1		   1.5557
2		 1.5246
3		 1.5267
2		   1.5047
1		 1.5192
2		 1.4995
1
PBEPBEultrafine         1.5121
1		                            
HSEh1PBE         1.5130
3		                            
Moller Plesset perturbation MP2FC 1.6063
2		 1.6548
3		 1.5104
3		 1.6579
3		 1.5468
3		 1.5468
3		 1.5384
3		 1.5391
3		 1.5391
3		 1.4808
3		   1.4925
3		 1.5602
3		 1.4814
3		 1.4703
3		 1.5542
3		 1.4764
3		 1.4666
3		 1.5216
1
MP2FU 1.6061
2		 1.6551
3		 1.4891
2		 1.6587
2		 1.5458
3		 1.5458
3		 1.5374
3		 1.5384
3		 1.5443
2		 1.4541
2		     1.5595
3		 1.4543
2		 1.4665
3		 1.5504
1		   1.4354
2		 1.5162
1
MP3         1.5256
3		                            
MP4   1.6589
2		     1.5059
3		     1.5309
1		 1.4809
2		         1.4977
3		          
B2PLYP         1.5160
3		   1.5130
3		                        
Configuration interaction CID   1.6277
2		 1.5124
2		 1.6282
2		 1.5281
3		     1.5218
3		                      
CISD   1.5725
1		 1.5291
2		 1.6214
2		 1.5312
3		     1.5467
2		                      
Quadratic configuration interaction QCISD   1.6111
3		 1.5521
2		 1.6355
2		 1.5271
3		 1.5387
2		 1.5216
3		 1.5183
3		 1.5183
3		 1.5240
2		     1.5399
3		 1.5255
2		         1.4909
1
QCISD(T)         1.5490
2		     1.5058
1		         1.5574
2		 1.5317
2		   1.5863
1		 1.5277
2		    
Coupled Cluster CCD   1.6316
2		 1.5064
2		 1.6322
2		 1.5321
3		 1.5491
2		 1.5388
2		 1.5253
3		 1.5429
2		 1.4761
2		     1.5438
3		 1.4780
2		   1.5534
2		 1.4716
2		    
CCSD         1.5380
2		     1.4935
1		                      
CCSD(T)   1.5826
1		     1.5128
1		 1.5128
1		 1.5121
1		 1.5047
1		 1.5047
1		   1.4983
1		   1.5552
2		 1.5216
3		   1.5504
2		 1.5247
2		   1.5016
1
CCSD(T)=FULL         1.5397
2		                            
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 1.6389
2		 1.6013
2		 1.9264
2		 1.6030
2		 1.6687
2		 1.6199
2
density functional B1B95 1.5561
1		 1.5040
1		        
B3LYP 1.6083
2		 1.5413
2		 1.6606
2		 1.5427
2		 1.6551
2		 1.5902
2
Moller Plesset perturbation MP2FC 1.6620
2		 1.5656
2		 1.5958
2		 1.5633
2		 1.6361
2		 1.6381
2
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.