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Bad vibrational frequency predictions

19 02 11 15 45

Calculated frequencies that differ from experiment by more than 400 cm-1 or have a ratio with experiment outside of 0.7 to 1.2 are listed

Calculated vibrational frequencies ("theory" in table) are calculated at ROMP2/6-31G(2df,p)
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H4+ Ethylene cation 4 torsion Au 84 -55 -139 -1.527
H2CS- thioformaldehyde anion 4 B1 450 230 -220 1.953
SiF2+ Silicon difluoride cation 2 A1 350 289 -61 1.210
CH3 Methyl radical 2 torsion A2" 606 460 -147 1.319
CH2 Methylene 1 A1 2806 3235 429 0.867
CH2OH Hydroxymethyl radical 9 torsion A 234 449 215 0.521
C2H3+ vinyl cation 2 A1 2217 3054 837 0.726
CHCl2 dichloromethyl radical 4 A' 190 310 120 0.612
CH2Cl chloromethyl radical 4 B1 402 113 -289 3.571
BF3+ boron trifluoride cation 5 B2 1791 2263 473 0.791
O2+ diatomic oxygen cation 1 Σg 1873 1389 -484 1.348
NF3 Nitrogen trifluoride 1 A1 1032 679 -353 1.521
NF3 Nitrogen trifluoride 2 A1 647 1087 440 0.595
NF3 Nitrogen trifluoride 3 E 907 511 -396 1.775
NF3 Nitrogen trifluoride 4 E 492 982 490 0.501
BCl3+ Boron Trichloride cation 3 E' 1104 1605 502 0.688
SF5 Sulfur pentafluoride 7 E 818 567 -251 1.443
AsSe Arsenic monoselenide 1 Σ 280 452 172 0.620
NaO2 Sodium superoxide 3 B2 333 559 226 0.596
GaP Gallium monophosphide 1 Σ 284 478 194 0.594
LiO2 Lithium dioxide 3 B2 509 954 445 0.534
C4 Carbon tetramer 3 Σu 1549 3797 2248 0.408
N3 azide radical 3 Πu 457 1183 726 0.386
BrO+ Bromine monoxide cation 1 Σ 840 1645 805 0.511
AlP Aluminum monophosphide 1 Σ 379 791 412 0.479
AlP Aluminum monophosphide 1 Σ 457 791 334 0.578
CHFCl Chlorofluoromethyl radical 6 A 540 414 -126 1.306
ClSO Sulfur chloride oxide 1 A' 1163 1633 470 0.712
ClONO chlorine nitrite 4 A' 406 336 -70 1.210
ZnCN Zinc monocyanide 3 Π 212 148 -64 1.435