return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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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 MP2/CEP-121G*
Calculated values were scaled by 0.9528.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C4H10O Ethoxy ethane 12 A1 240 185 -55 1.298
C4H10O Ethoxy ethane 20 A2 137 76 -61 1.812
CH3CONH2 Acetamide 20 A 259 390 131 0.663
CH3COOH Acetic acid 18 torsion A" 93 52 -41 1.790
CH3OH Methyl alcohol 12 torsion A" 200 337 137 0.593
C6H6 Benzene 7 B2g 995 775 -220 1.285
C6H6 Benzene 8 B2g 703 -870 -1573 -0.808
C6H6 Benzene 19 E2u 975 708 -267 1.377
CH3CCl3 Ethane, 1,1,1-trichloro- 6 torsion A2 214 323 109 0.663
C2H2 Acetylene 4 Πg 612 334 -278 1.834
HCN+ hydrogen cyanide cation 1 Σ 3050 3809 759 0.801
HCN+ hydrogen cyanide cation 2 Σ 1800 2794 994 0.644
CH3CCH propyne 9 E 633 499 -134 1.268
CHONH2 formamide 12 torsion A" 289 -282 -571 -1.023
CH3SCH3 Dimethyl sulfide 11 torsion A2 175 139 -36 1.261
CH3SCH3+ dimethyl sulfide cation 15 B1 172 128 -44 1.347
C3F8 perfluoropropane 13 A2 276 214 -62 1.287
CH3COOCH3 methyl acetate 27 torsion A" 110 17 -93 6.561
C13H10 Fluorene 24 A2 977 737 -240 1.325
C13H10 Fluorene 25 A2 944 708 -236 1.333
C13H10 Fluorene 27 A2 782 616 -166 1.270
C13H10 Fluorene 29 A2 566 262 -304 2.163
C13H10 Fluorene 30 A2 430 234 -196 1.839
C13H10 Fluorene 31 A2 270 122 -148 2.218
C13H10 Fluorene 32 A2 129 -795 -924 -0.162
C10H8 naphthalene 10 Au 970 711 -259 1.364
C10H8 naphthalene 12 Au 581 165 -416 3.530
C10H8 naphthalene 13 Au 195 -693 -888 -0.281
C10H8 naphthalene 14 B1g 943 719 -224 1.311
C10H8 naphthalene 16 B1g 386 304 -82 1.271
C10H8 naphthalene 25 B2g 980 759 -221 1.291
C10H8 naphthalene 26 B2g 876 665 -211 1.317
C10H8 naphthalene 27 B2g 770 262 -508 2.934
C10H8 naphthalene 28 B2g 461 -1328 -1789 -0.347
C10H8 naphthalene 45 B3u 958 737 -221 1.300
C10H8 naphthalene 47 B3u 476 334 -142 1.425
C9H8 Indene 36 A" 917 721 -197 1.273
C9H8 Indene 40 A" 690 443 -247 1.557
C9H8 Indene 41 A" 549 313 -236 1.754
C9H8 Indene 42 A" 415 302 -112 1.371
C9H8 Indene 43 A" 388 187 -201 2.076
C9H8 Indene 45 A" 189 -689 -877 -0.274
C6H4Cl2 1,2-dichlorobenzene 12 A2 975 730 -245 1.336
C6H4Cl2 1,2-dichlorobenzene 14 A2 695 334 -361 2.081
C6H4Cl2 1,2-dichlorobenzene 15 A2 504 122 -382 4.135
C6H4Cl2 1,2-dichlorobenzene 16 A2 152 -910 -1062 -0.167
C6H4Cl2 1,2-dichlorobenzene 17 B1 940 727 -213 1.293
C6H4Cl2 1,4-dichlorobenzene 7 Au 951 716 -235 1.329
C6H4Cl2 1,4-dichlorobenzene 16 B2g 687 264 -423 2.601
C6H4Cl2 1,4-dichlorobenzene 17 B2g 298 -797 -1095 -0.374
C6H4Cl2 1,4-dichlorobenzene 29 B3u 485 379 -106 1.281
C6H4Cl2 1,4-dichlorobenzene 30 B3u 122 94 -28 1.303
C6H4O2 parabenzoquinone 16 B2g 794 496 -298 1.602
C6H4O2 parabenzoquinone 17 B2g 241 -302 -543 -0.799
C6H4O2 parabenzoquinone 30 B3u 109 75 -34 1.454
CH3CH2CH2CH3 Butane 5 Ag 1442 408 -1034 3.538
CH3CH2CH2CH3 Butane 8 Ag 1151 817 -334 1.408
CH3CH2CH2CH3 Butane 30 Bu 1461 2915 1454 0.501
CH3CH2CH2CH3 Butane 35 Bu 964 3006 2042 0.321
C3H6O 2-Propen-1-ol 24 A 188 105 -83 1.794
CH2ClCHO chloroacetaldehyde 15 torsion A 27 52 25 0.515
CH2ClCHO chloroacetaldehyde 15 A" 59 142 83 0.416
C4H2O3 Maleic Anhydride 11 A2 275 192 -83 1.434
C5H12 Pentane 23 A2 131 92 -39 1.430
C3H2N2 Malononitrile 6 A1 167 130 -37 1.283
C4H5N Pyrrole 10 A2 864 674 -190 1.281
C4H5N Pyrrole 12 A2 614 407 -207 1.507
C4H4O Furan 11 A2 603 385 -218 1.566
C4H4S Thiophene 11 A2 567 418 -149 1.358
CHSNH2 thioformamide 12 A" 393 -128 -521 -3.075
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 torsion A2 193 140 -53 1.379
C3F6 hexafluoropropene 21 A" 60 35 -25 1.710
C2Cl4 Tetrachloroethylene 7 B2g 512 344 -168 1.490
C5H8 Cyclopentene 18 torsion A' 254 175 -79 1.451
C4H4N2 Pyridazine 12 A2 751 433 -318 1.735
C4H4N2 Pyridazine 13 A2 421 217 -204 1.937
C6F6 hexafluorobenzene 7 B2g 719 249 -470 2.890
C6F6 hexafluorobenzene 8 B2g 205 -138 -343 -1.487
NH2CN cyanamide 5 torsion A' 408 731 323 0.558
C4H6O2 2,3-Butanedione 21 torsion Bg 240 108 -132 2.218
CH(CN)3 tricyanomethane 12 E 149 117 -32 1.272
C4H2 Diacetylene 6 Πg 627 1132 505 0.554
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 996 -395 1.397
CH2CO Ketene 6 B1 528 396 -132 1.333
C6H6 Fulvene 15 A2 494 370 -124 1.335
C3H6O Oxetane 18 B1 90 -88 -178 -1.017
C3O2 Carbon suboxide 7 Πu 61 169 108 0.360
HCNO fulminic acid 5 torsion Π 224 -386 -610 -0.581
C6H4F2 1,4-difluorobenzene 16 B2g 692 385 -307 1.797
C6H4F2 1,4-difluorobenzene 18 B2g 374 -292 -666 -1.282
C6H4Cl2 1,3-dichlorobenzene 13 A2 532 400 -132 1.328
C6H4Cl2 1,3-dichlorobenzene 15 B1 964 747 -217 1.290
C6H4Cl2 1,3-dichlorobenzene 18 B1 672 359 -313 1.873
C6H4Cl2 1,3-dichlorobenzene 19 B1 433 153 -280 2.825
C6H4Cl2 1,3-dichlorobenzene 20 B1 175 -705 -880 -0.248
C5H8 1,4-Pentadiene 16 A 137 289 152 0.474
HCCCl Chloroacetylene 4 Π 604 474 -130 1.273
HCCCl Chloroacetylene 5 Π 326 144 -182 2.267
P(CH3)3 trimethylphosphine 22 E 259 181 -78 1.427
C5H6S Thiophene, 3-methyl- 27 A" 594 429 -165 1.386
CH3SSCH3 Disulfide, dimethyl 13 torsion A 117 86 -31 1.363
CO+ carbon monoxide cation 1 Σ 2184 2714 530 0.805
C6H6 Benzvalene 10 A1 996 728 -268 1.369
C2F2 difluoroacetylene 4 Πg 270 104 -166 2.603
H2CS- thioformaldehyde anion 4 B1 450 -178 -628 -2.527
CH2CHSH Ethenethiol 13 A" 972 737 -235 1.320
CH2ClCCCl 1,3-dichloropropyne 14 A" 337 174 -163 1.940
CH2ClCCCl 1,3-dichloropropyne 15 A" 176 135 -41 1.306
LiOH lithium hydroxide 3 Π 257 385 129 0.665
SiF2+ Silicon difluoride cation 2 A1 350 275 -75 1.271
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.677
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 305 -151 1.496
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 103 -68 1.665
CH2NH+ Methanimine cation 4 A' 1370 1785 415 0.767
CN Cyano radical 1 Σ 2042 2661 619 0.768
C6H5O phenoxy radical 19 B1 472 175 -297 2.692
C2H Ethynyl radical 2 Σ 1841 2307 466 0.798
C2H Ethynyl radical 3 torsion Π 372 785 413 0.474
C2H+ Ethynyl cation 3 Π 550 802 253 0.685
CH3OO methylperoxy radical 12 torsion A" 170 126 -44 1.354
CH3 Methyl radical 2 torsion A2" 606 405 -201 1.496
C6H5 phenyl 17 B1 655 452 -203 1.448
C6H5 phenyl 18 B1 415 150 -265 2.768
CH2OH Hydroxymethyl radical 8 torsion A 482 758 276 0.636
CH2OH Hydroxymethyl radical 9 torsion A 234 448 214 0.522
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 854 -282 1.330
C6H8 (Z)-hexa-1,3,5-triene 18 A2 331 248 -83 1.334
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 103 -161 2.570
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 88 -270 4.068
HCCN cyanomethylene 5 Π 129 -540 -668 -0.239
CCl3 Trichloromethyl radical 2 A1 251 366 115 0.685
C6H6 Trimethylenecycopropane 9 A2" 885 693 -192 1.277
CHCl2 dichloromethyl radical 4 A' 190 293 103 0.649
C4H6 Methylenecyclopropane 17 B1 360 253 -107 1.423
CH2Cl chloromethyl radical 4 B1 402 -323 -725 -1.245
HNC+ hydrogen isocyanide cation 2 Σ 2195 2632 436 0.834
ClFO3 Perchloryl fluoride 6 E 405 314 -91 1.288
BF3+ boron trifluoride cation 5 B2 1791 3274 1483 0.547
O2+ diatomic oxygen cation 1 Σg 1873 1217 -656 1.539
HN3+ Hydrazoic acid cation 2 A' 1850 3189 1339 0.580
HN3+ Hydrazoic acid cation 4 A' 850 644 -206 1.321
MgF2 Magnesium fluoride 3 Πu 165 116 -49 1.419
HOCl+ hypochlorous acid cation 3 A' 830 1308 478 0.634
O3 Ozone 3 B2 1042 2339 1297 0.445
NO Nitric oxide 1 Σ 1876 3905 2029 0.480
NO2 Nitrogen dioxide 3 B2 1618 2039 421 0.794
NO2+ Nitrogen dioxide cation 3 Πu 639 500 -139 1.279
N2O4 Dinitrogen tetroxide 9 B2u 265 177 -88 1.501
N2O3 Dinitrogen trioxide 9 torsion A" 63 150 87 0.421
C3O Tricarbon monoxide 5 Π 109 241 132 0.452
NaO2 Sodium superoxide 3 B2 333 7486 7153 0.044
Li2O dilithium oxide 3 Πu 112 83 -29 1.345
FO Oxygen monofluoride 1 Σ 1033 2267 1234 0.456
SiC2 Silicon dicarbide 3 B2 196 -112 -308 -1.756
C3 carbon trimer 3 Πu 63 307 244 0.206
C5H5- cylopentadienyl anion 8 E1" 625 416 -209 1.503
C5H5- cylopentadienyl anion 14 E2" 600 104 -496 5.751
LiO2 Lithium dioxide 3 B2 509 2580 2071 0.197
MgOH magnesium hydroxide 3 torsion Π 188 65 -123 2.907
C4 Carbon tetramer 4 Πg 323 524 201 0.617
SiH2D2 silane-d2 6 B1 2183 1563 -620 1.396
SiH2D2 silane-d2 8 B2 1601 2163 562 0.740
PO Phosphorus monoxide 1 Σ 1220 5217 3997 0.234
AlO Aluminum monoxide 1 Σ 965 589 -376 1.638
SCN thiocyanato radical 1 Σ 1942 2459 517 0.790
ClOO chloroperoxy radical 2 A' 414 1024 610 0.404
ClOO chloroperoxy radical 3 A' 201 466 265 0.432
B4H10 Tetraborane(10) 11 A1 785 570 -215 1.377
B4H10 Tetraborane(10) 12 A1 559 231 -328 2.420
B4H10 Tetraborane(10) 19 A2 662 410 -252 1.614
B4H10 Tetraborane(10) 36 B2 236 355 119 0.664
FSN Thiazyl fluoride 3 A' 366 287 -79 1.276
BH3PH3 borane phosphine 12 E 447 353 -94 1.266
B5H9 pentaborane9 13 B1 240 610 370 0.394
B5H9 pentaborane9 16 B2 1036 774 -262 1.339
B5H9 pentaborane9 18 B2 600 474 -126 1.266
B5H9 pentaborane9 22 E 1409 1074 -335 1.312
OPCl Phosphorus oxychloride 2 A' 308 478 170 0.645
OPCl Phosphorus oxychloride 3 A' 492 279 -213 1.762
NCO isocyanato radical 1 Σ 1921 2353 432 0.816
H2POH Phosphinous acid 9 A" 375 251 -124 1.496
Mg2 Magnesium diatomic 1 Σg 48 31 -17 1.561
ClOF3 Chlorine trifluoride oxide 5 A' 319 247 -72 1.294
ClOF3 Chlorine trifluoride oxide 6 A' 224 175 -49 1.277
ClOF3 Chlorine trifluoride oxide 9 A" 412 315 -97 1.310
CHFCl Chlorofluoromethyl radical 6 A 540 385 -155 1.404
H2CNCN cyanamide, methylene 3 A' 2208 2981 773 0.741
SNO Nitrogen oxide sulfide 3 A' 792 503 -289 1.576
ONNO NO dimer 3 A1 135 282 148 0.477
ONNO NO dimer 4 torsion A2 117 259 142 0.452
AlNC Aluminum isocyanide 3 Π 100 152 52 0.656
ClONO chlorine nitrite 4 A' 406 319 -87 1.273
ONONO Nitrosyl nitrite 9 B2 380 240 -140 1.585