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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 MP4/Def2TZVPP
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
HCN+ hydrogen cyanide cation 1 Σ 3050 3599 549 0.847
HCN+ hydrogen cyanide cation 2 Σ 1800 2793 993 0.645
CH2I2 Diiodomethane 3 A1 704 502 -202 1.402
CH2I2 Diiodomethane 4 A1 285 118 -167 2.408
CH2I2 Diiodomethane 7 B1 896 726 -170 1.234
CH2I2 Diiodomethane 9 B2 738 611 -127 1.207
CH3SCH3+ dimethyl sulfide cation 15 B1 172 123 -49 1.400
CH3CH2CH2CH3 Butane 5 Ag 1442 422 -1020 3.415
CH3CH2CH2CH3 Butane 8 Ag 1151 849 -302 1.356
CH3CH2CH2CH3 Butane 36 Bu 271 3114 2843 0.087
F2CCCF2 tetrafluoroallene 5 B2 2052 728 -1324 2.820
F2CCCF2 tetrafluoroallene 6 B2 1030 581 -449 1.772
F2CCCF2 tetrafluoroallene 7 B2 581 391 -190 1.486
CI4 tetraiodomethane 3 T2 555 185 -370 3.004
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 688 -2391 4.474
CO+ carbon monoxide cation 1 Σ 2184 2737 553 0.798
H2CS- thioformaldehyde anion 4 B1 450 228 -222 1.975
CaO Calcium monoxide 1 Σ 723 1800 1078 0.401
CFCl2 dichlorofluoromethyl radical 2 A' 747 617 -130 1.210
CN Cyano radical 1 Σ 2042 2720 678 0.751
CH2Cl chloromethyl radical 4 B1 402 131 -271 3.067
HN3+ Hydrazoic acid cation 2 A' 1850 3014 1164 0.614
IF5 pentafluoroiodine 2 A1 616 311 -305 1.979
CaBr2 Calcium dibromide 3 Πu 72 40 -32 1.789
NO Nitric oxide 1 Σ 1876 3406 1530 0.551
NaO2 Sodium superoxide 1 A1 1094 2045 951 0.535
NaO2 Sodium superoxide 3 B2 333 1271 938 0.262
C3 carbon trimer 3 Πu 63 193 129 0.329
XeF4 Xenon tetrafluoride 5 B2u 216 160 -56 1.353
SiH2D2 silane-d2 6 B1 2183 1644 -539 1.328
SiH2D2 silane-d2 8 B2 1601 2274 673 0.704
OPCl Phosphorus oxychloride 2 A' 308 498 190 0.618
OPCl Phosphorus oxychloride 3 A' 492 301 -191 1.636
CHFCl Chlorofluoromethyl radical 6 A 540 409 -131 1.319
H2CNCN cyanamide, methylene 3 A' 2208 3088 880 0.715
H2CNCN cyanamide, methylene 4 A' 1621 2136 515 0.759
SNO Nitrogen oxide sulfide 1 A' 1527 3791 2264 0.403
SNO Nitrogen oxide sulfide 3 A' 792 -5539 -6332 -0.143
INO Nitrosyl iodide 2 A' 216 470 254 0.460
INO Nitrosyl iodide 3 A' 470 220 -250 2.136