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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/daug-cc-pVDZ
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 torsion A" 200 296 96 0.676
CH3CCH propyne 10 E 328 253 -75 1.299
C3O2 Carbon suboxide 7 Πu 61 -92 -153 -0.665
CO+ carbon monoxide cation 1 Σ 2184 2710 526 0.806
CH2NH+ Methanimine cation 4 A' 1370 1853 483 0.740
CN Cyano radical 1 Σ 2042 2649 606 0.771
C2H- Ethynyl anion 3 Π 505 407 -98 1.240
CH2Cl chloromethyl radical 4 B1 402 -151 -553 -2.661
HNC+ hydrogen isocyanide cation 2 Σ 2195 2651 456 0.828
SeO2 Selenium dioxide 2 A1 373 309 -63 1.204
HN3+ Hydrazoic acid cation 2 A' 1850 3077 1227 0.601
HOCl+ hypochlorous acid cation 3 A' 830 1345 515 0.617
NO Nitric oxide 1 Σ 1876 3618 1742 0.518
C4 Carbon tetramer 4 Πg 323 -196 -519 -1.651
C4 Carbon tetramer 5 Πu 160 123 -37 1.303
SiH2D2 silane-d2 6 B1 2183 1621 -562 1.347
SiH2D2 silane-d2 8 B2 1601 2242 641 0.714
NH4 Ammonium radical 1 A1 2552 3000 448 0.851
BH3PH3 borane phosphine 12 E 447 370 -77 1.210
CHFCl Chlorofluoromethyl radical 6 A 540 398 -142 1.357
H2CNCN cyanamide, methylene 3 A' 2208 3078 870 0.717
H2CNCN cyanamide, methylene 4 A' 1621 2105 484 0.770
SNO Nitrogen oxide sulfide 3 A' 792 521 -271 1.521