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XIII.F.1. (III.B.7.a.) (XVIII.B.1.)

Bad Vibrational Frequency Predictions

Unscaled vibrational frequencies calculated at MP2/6-31G* are generally lower than frequencies calculated at HF/6-31G*. This page lists vibrational modes for which that is not true, which may be a warning of a vibrational mode for which the harmonic assumption is poor, or the calculation at HF or MP2 is a poor description of the molecule. The vibrational numbering may not align for all calculations. This will result in some molecules listed here for which the vibrational frequency calculations are reasonable. Click on an entry for a comparison of all the vibrational frequencies for that molecule at HF/6-31G* and MP2/6-31G*.
Formula Name Mode Number Symmetry Frequency (cm-1) IR Intensity (km mol-1) Reduced mass
HF MP2 ratio HF MP2 ratio HF MP2 ratio
NO3+ nitrogen trioxide cation 4 E' 2202i 567 -3.8821 4245.32 65.54 64.7785 14.43 15.97 0.9038
NO3+ nitrogen trioxide cation 4 E' 2202i 567 -3.8821 4245.31 65.54 64.7783 14.43 15.97 0.9038
C3+ carbon trimer cation 3 Πu 145i 290 -0.4999 17.74 1.28 13.8740 12.00 12.00 1.0000
C3+ carbon trimer cation 4 Πu 145i 290 -0.4999 17.74 1.28 13.8740 12.00 12.00 1.0000
N2O5 Dinitrogen pentoxide 15 B 13i 33 -0.3817 0.87 14.58 0.0599 15.97 15.95 1.0018
NO3+ nitrogen trioxide cation 3 E' 958 10166 0.0942 93.38 0.00   15.96 14.43 1.1064
NO3+ nitrogen trioxide cation 3 E' 958 10166 0.0942 93.38 0.00   15.96 14.43 1.1064
ZnCH2 Zinc methylene 4 B1 3193 25950 0.1230 5.81 0.00   1.26 1.25 1.0043
HCCO ketenyl radical 5 A' 95 618 0.1537 168.96 29.38 5.7504 1.45 9.74 0.1486
BrF- bromine fluoride anion 1 Σ 93 495 0.1879 13.10 138.08 0.0949 22.28 22.28 1.0000
C3H6O2 1,3-Dioxolane 14 A 262 1253 0.2088 0.61 3.19 0.1899 2.09 1.18 1.7784
C8H14 Bicyclo[2.2.2]octane 11 A1 26 125 0.2101 0.00 0.00   1.73 1.75 0.9923
C2H5Br Ethyl bromide 11 A' 310 1471 0.2106 2.67 6.03 0.4434 3.25 1.24 2.6215
BC+ boron monocarbide cation 1 Σ 448 1647 0.2720 0.28 640.85 0.0004 11.46 11.46 1.0000
N3 azide radical 2 Σu 1705 5923 0.2878 654.41 0.00   14.00 14.00 1.0000
NaO+ sodium oxide cation 1 Σ 58 190 0.3046 21.81 16.96 1.2857 18.28 18.28 1.0000
MgOH magnesium hydroxide 3 A' 85 258 0.3276 199.29 157.91 1.2620 1.17 1.21 0.9621
C5H10O Oxetane, 3,3-dimethyl- 24 A' 46 139 0.3336 7.11 6.88 1.0333   3.24  
PO Phosphorus monoxide 1 Σ 1404 4102 0.3423 68.38 91759.10 0.0007 19.15 19.15 1.0000
BC boron monocarbide 1 Σ 933 2570 0.3631 75.22 715.95 0.1051 11.46 11.46 1.0000
C2H5Br Ethyl bromide 10 A' 601 1550 0.3875 31.00 1.24 25.0231 4.16 1.10 3.7705
C5H5NO 2(3H)-Pyridinone 30 A 38 95 0.3986 2.58 2.01 1.2839 3.36 4.29 0.7838
C4H6O Furan, 2,3-dihydro- 27 ?a 66 164 0.4027 2.74 2.10 1.3065 1.99 1.98 1.0069
O3+ Ozone cation 3 B2 1207 2986 0.4043 614.36 203.71 3.0159 15.99 15.99 1.0000
NCl+ nitrogen monochloride cation 1 Σ 748 1822 0.4102 2.24 1886.11 0.0012 16.90 16.90 1.0000
PS phosphorus sulfide 1 Σ 547 1252 0.4374 0.05 870.74 0.0001 31.46 31.46 1.0000
BeN- Beryllium mononitride anion 1 Σ 1379 3103 0.4445 271.51     10.47 10.47 1.0000
SO2+ Sulfur dioxide cation 3 B2 1845 3916 0.4712 874.03 42541.27 0.0205 20.65 20.83 0.9912
FO Oxygen monofluoride 1 Σ 1176 2489 0.4722 37.37 699.96 0.0534 17.24 17.24 1.0000
NaO- sodium oxide anion 1 Σ 384 797 0.4809 109.93 312.57 0.3517 18.28 18.28 1.0000
SiN+ silicon mononitride cation 1 Σ 601 1241 0.4845 30.69 603.60 0.0508 16.80 16.80 1.0000
Na2+ sodium dimer cation 1 Σg 121 246 0.4915 0.00 0.06 0.0000 22.99 22.99 1.0000
C3H6O2 1,3-Dioxolane 6 A 1538 3084 0.4986 16.27 109.18 0.1490 1.40 1.05 1.3248
PN+ phosphorus nitride cation 1 Σ 758 1513 0.5010 66.96 72.41 0.9247 16.88 16.88 1.0000
C2H5Br Ethyl bromide 6 A' 1565 3111 0.5030 2.43 13.25 0.1834 1.23 1.04 1.1872
HNO2+ nitrous acid cation 2 A' 1562 3056 0.5111 114.83 3048.57 0.0377 1.30 11.23 0.1156
C2H5Br Ethyl bromide 4 A' 1642 3169 0.5182 1.41 8.55 0.1648 1.06 1.06 0.9968
C6H12 Pentane, 3-methylene- 48 ?a 33 63 0.5252 0.01 0.01 0.3704 2.29 2.37 0.9669
C2H5Br Ethyl bromide 5 A' 1638 3111 0.5264 1.34 13.22 0.1016 1.10 1.04 1.0619
C2H3+ vinyl cation 9 B2 336 637 0.5277 55.99 31.42 1.7819 1.60 1.68 0.9528
Li2+ lithium diatomic cation 1 Σg 260 488 0.5327 0.00 0.00   7.02 7.02 1.0000
C6H4 Benzyne 24 B2 316 591 0.5343 189.90 10.12 18.7737 10.75 9.54 1.1269
C3H6O2 1,3-Dioxolane 5 A 1681 3090 0.5439 4.24 1.47 2.8797 1.11 1.07 1.0401
C6H5CH3 toluene 39 A" 33 59 0.5548 0.17 0.20 0.8136 1.04 1.04 1.0003
C3H6O2 1,3-Dioxolane 4 A 1723 3096 0.5567 10.73 60.55 0.1772 1.11 1.06 1.0403
C2H5+ Ethyl cation 15 B2 428 759 0.5636 321.96 144.04 2.2353 1.35 1.42 0.9508
AlN- aluminum mononitride anion 1 Σ 610 1074 0.5675 40.41 157.16 0.2571 16.76 16.76 1.0000
NO Nitric oxide 1 Σ 2221 3914 0.5676 69.51 2717.62 0.0256 14.87 14.87 1.0000
NNH Dinitrogen monohydride 2 A' 1663 2829 0.5880 7.74 69.60 0.1112 8.60 1.72 4.9883
NH3NH3 Ammonia Dimer 18 Bu 61 103 0.5888 285.31 321.92 0.8863 1.04 1.04 0.9982
ZnCH2 Zinc methylene 4 A' 360 605 0.5947 45.22 5.36 8.4293 6.39 3.68 1.7361
HNO+ Nitrosyl hydride cation 1 A' 3153 5301 0.5947 275.34 15096.72 0.0182 1.07 12.44 0.0864
AlO+ aluminum monoxide cation 1 Σ 805 1352 0.5956 116.48 590.27 0.1973 18.85 18.85 1.0000
BN+ boron nitride cation 1 Σ 1535 2576 0.5957 46.36 2704.23 0.0171 12.15 12.15 1.0000
BC+ boron monocarbide cation 1 Σ 894 1497 0.5975 102.68 374.68 0.2741 11.46 11.46 1.0000
Na2O disodium monoxide 2 A1 49 83 0.5984 147.51 16.48 8.9510 17.36 19.13 0.9073
NH2CSNH2 Thiourea 9 A 234 391 0.5993 88.36 157.62 0.5606 1.15 1.13 1.0199
CH3NO2 Methane, nitro- 15 A" 22 36 0.6100 0.02 0.05 0.4491 1.10 1.09 1.0018
O3 Ozone 3 B2 1454 2379 0.6112 786.18 1481.69 0.5306 15.99 15.99 1.0000
HCCCN+ Cyanoacetylene cation 2 Σ 2011 3286 0.6120 100.07 35.47 2.8217 7.49 1.23 6.0943
CCl- carbon monochloride anion 1 Σ 272 444 0.6138 127.71 94.39 1.3530 14.42 14.42 1.0000
H2OCH3OCH3 water dimethylether dimer 29 A 55 88 0.6172 9.69 11.38 0.8511 2.83 2.99 0.9465
C3H5Cl3 Propane, 1,2,3-trichloro- 27 A" 18 29 0.6195 1.76 1.18 1.4900 2.70 2.68 1.0059
SiN Silicon nitride 1 Σ 915 1476 0.6196 41.88 359.03 0.1166 16.80 16.80 1.0000
BCl- boron monochloride anion 1 Σ 269 433 0.6225 171.90 143.38 1.1988 13.17 13.17 1.0000
N2O4 Dinitrogen tetroxide 4 Au 65 105 0.6227 0.00 0.00   15.99 15.99 1.0000
HNO2+ nitrous acid cation 5 A' 445 713 0.6250 15.99 6.30 2.5396 8.84 6.20 1.4247
C3H6O2 1,3-Dioxolane 13 A 806 1285 0.6268 0.37 6.76 0.0554 8.22 1.24 6.6321
CH3CN+ Acetonitrile cation 1 ?a 28769 45845 0.6275 0.00 0.00   1.38 1.36 1.0147
CH2CHCONH2 Acrylamide 23 A 181 286 0.6316 254.77 6.55 38.9246 1.50 3.22 0.4677
H2O2+ Hydrogen peroxide cation 5 Bu 3689 5812 0.6347 1219.06 888014.90 0.0014 1.07 1.07 1.0000
SO- sulfur monoxide anion 1 Σ 736 1156 0.6364 39.62 6.68 5.9312 19.19 19.19 1.0000
HCS Thioformyl radical 2 A' 1032 1606 0.6427 0.90 295.82 0.0030 7.07 8.70 0.8130
NF3- Nitrogen trifluoride anion 3 E 422 656 0.6429 85.40 1561.86 0.0547 16.04 14.99 1.0695
NF3- Nitrogen trifluoride anion 3 E 422 656 0.6429 85.40 1561.81 0.0547 16.04 14.99 1.0695
NCl- nitrogen monochloride anion 1 Σ 375 581 0.6457 104.50 27.63 3.7818 16.90 16.90 1.0000
S3- Sulfur trimer anion 3 B2 519 798 0.6499 959.81 25.31 37.9263 31.97 31.97 1.0000
N2O+ Nitrous oxide cation 1 Σ 2140 3290 0.6504 1.06 56.86 0.0187 14.00 14.01 0.9996
CH6N4S Carbonothioic dihydrazide 30 A 55 84 0.6532 13.04 38.38 0.3397 3.89 3.07 1.2659
ClOO chloroperoxy radical 2 A' 714 1092 0.6540 18.33 33.36 0.5495 17.47 17.03 1.0258
N2O3 Dinitrogen trioxide 9 A" 115 174 0.6611 1.66 0.14 11.7307 14.93 15.09 0.9893
SeO- selenium monoxide anion 1 Σ 588 887 0.6631 0.17 91.90 0.0018 18.46 18.46 1.0000
BeN Beryllium mononitride 1 Σ 1099 1642 0.6689 170.87 3231.91 0.0529 10.47 10.47 1.0000
C10H8 naphthalene 9 Ag 551 824 0.6690 0.00 0.00   6.60 1.29 5.1328
NS Mononitrogen monosulfide 1 Σ 894 1332 0.6712 23.57 56.59 0.4165 16.90 16.90 1.0000
C3H6S Thietane 14 A' 129 192 0.6714 1.90 1.74 1.0927 1.77 1.77 0.9962
ZnO zinc monoxide 1 Σ 673 1001 0.6726 49.30 391.72 0.1259 18.82 18.82 1.0000
C2H5Br Ethyl bromide 9 A' 1048 1550 0.6759 12.33 1.24 9.9586 1.93 1.10 1.7523
NO3 Nitrogen trioxide 1 A1 1597 2360 0.6767 227.34 2443.48 0.0930 15.00 14.46 1.0373
C2H Ethynyl radical 3 Π 557 818 0.6810 31.90 15.54 2.0527 1.33    
C2H Ethynyl radical 3 Π 557 818 0.6810 31.90 15.54 2.0527 1.33    
CH3CONH2 Acetamide 20 A 224 326 0.6865 306.52 267.96 1.1439 1.23 1.24 0.9892
N2O5 Dinitrogen pentoxide 15 A" 27 39 0.6876 0.67 0.00 2228.0000 15.95 15.96 0.9997
HNO+ Nitrosyl hydride cation 2 A' 2037 2962 0.6876 34.70 395.51 0.0877 10.04 1.06 9.4460
ClOO chloroperoxy radical 1 A' 1191 1729 0.6890 24.23 139.43 0.1738 16.07 18.09 0.8884
HCCCN+ Cyanoacetylene cation 3 Σ 1716 2481 0.6918 428.74 717.54 0.5975 11.71 6.19 1.8908
CN Cyano radical 1 Σ 1982 2863 0.6925 13.45 20.37 0.6600 12.85 12.85 1.0000
CCl2- dichloromethylene anion 3 B2 332 477 0.6944 451.65 270.22 1.6714 13.99 13.98 1.0006
CSe+ Carbon monoselenide cation 1 Σ 1019 1459 0.6981 3.17 183.79 0.0172 13.50 13.50 1.0000
C2H+ Ethynyl cation 3 Π 551 787 0.7005 60.92 44.60 1.3661 1.32 1.33 0.9941
C3O2+ Carbon suboxide cation 3 Σu 2093 2974 0.7038 1327.09 7600.29 0.1746 12.96 12.97 0.9993
HCN+ hydrogen cyanide cation 2 Σ 2084 2958 0.7045 47.81 336.76 0.1420 5.53 1.25 4.4325
C6H10 3-Hexyne 22 A2 5 7 0.7056 0.00 0.00   1.83 1.85 0.9922
C6H5CHCH2 Styrene 42 A 58 82 0.7058 0.09 0.13 0.6522 2.37 2.55 0.9289
Be2- Beryllium dimer anion 1 sgg 357 505 0.7077 0.00 0.00   9.01 9.01 1.0000
SiC- silicon monocarbide anion 1 Σ 766 1072 0.7145 8.10 20.15 0.4019 14.48 14.48 1.0000
MgO magnesium oxide 1 Σ 768 1071 0.7170 115.76 1148.54 0.1008 18.45 18.45 1.0000
BN- boron nitride anion 1 Σ 1616 2217 0.7287 83.27 198.04 0.4205 12.15 12.15 1.0000
ClO- chlorine monoxide anion 1 Σ 519 709 0.7316 48.32 0.67 72.0386 19.28 19.28 1.0000
CO2+ Carbon dioxide cation 3 Πu 426 580 0.7356 41.87 32.69 1.2807 12.88 12.88 1.0000
Ne2 Neon dimer 1 sgg 78 106 0.7362 0.00 0.00   19.99 19.99 1.0000
ClO+ chlorine monoxide cation 1 Σ 1031 1391 0.7410 160.79 0.01 12863.3100 19.28 19.28 1.0000
C2H3OC2H5 Ethene, ethoxy- 33 A 51 69 0.7420 1.37 1.54 0.8921 2.09 2.13 0.9845
C2H Ethynyl radical 2 Σ 1854 2484 0.7463 1.59 8.92 0.1780 6.65    
SiS+ silicon monosulfide cation 1 Σ 690 924 0.7464 0.23 163.08 0.0014 29.71 29.71 1.0000
Cu2 Copper dimer 1 Σg 304 405 0.7491 0.00 0.00   62.93 62.93 1.0000
C2H5Br Ethyl bromide 8 A' 1172 1562 0.7500 0.82 2.89 0.2843 1.81 1.05 1.7221
C3H6O2 1,3-Dioxolane 12 A 1031 1371 0.7522 8.28 0.04 192.9044 2.40 1.23 1.9520
C3H6O2 1,3-Dioxolane 11 A 1071 1420 0.7539 2.18 9.69 0.2248 4.42 1.35 3.2828
CH3CN+ Acetonitrile cation 3 A' 2213 2927 0.7561 80.86 167.49 0.4828 12.22 1.11 10.9643
OCS+ Carbonyl sulfide cation 1 Σ 2361 3119 0.7570 209.49 2772.23 0.0756 13.41 13.23 1.0133
PN- phosphorus nitride anion 1 Σ 877 1158 0.7573 52.97 32.88 1.6109 16.88 16.88 1.0000
HCCCN+ Cyanoacetylene cation 6 Π 489 646 0.7577 3.81 0.12 31.0204 7.78 11.81 0.6590
H2OH2CO water formaldehyde dimer 15 A 116 152 0.7604 46.36 32.88 1.4099 3.35 3.60 0.9310
FO+ fluorine monoxide cation 1 Σ 1340 1745 0.7676 89.82 172.40 0.5210 17.24 17.24 1.0000
HCl- hydrogen chloride anion 1 Σ 70 91 0.7681 2.37 11.89 0.1994 1.04 1.04 1.0000
AlN Aluminum nitride 1 Σ 793 1032 0.7684 20.41 173.74 0.1175 16.76 16.76 1.0000
H2OHCOOH Water formic acid dimer 1 15 A 134 174 0.7704 92.56 96.20 0.9621 1.12 1.05 1.0763
Mg2- magnesium dimer anion 1 Σg 79 103 0.7719 0.00 0.00   23.99 23.99 1.0000
CH3 Methyl radical 2 A2" 308 398 0.7730 83.24 94.03 0.8852   1.24  
CuH Copper monohydride 1 Σ 1783 2302 0.7744 420.27 431.66 0.9736 1.02 1.02 1.0000
HBr- hydrogen bromide anion 1 Σ 150 193 0.7756 10.47 31.62 0.3311 1.02 1.02 1.0000
AlS+ aluminum monosulfide cation 1 Σ 567 730 0.7767 0.02 43.81 0.0005 29.06 29.06 1.0000
C3O2+ Carbon suboxide cation 1 Σg 2305 2965 0.7775 0.00 0.00   13.05 13.07 0.9982
NCO isocyanato radical 1 Σ 1959 2509 0.7808 20.16 1008.10 0.0200 12.73 13.00 0.9796
C4H6(CH3)2 dimethylcyclobutane A' 148 190 0.7813 0.00 0.01 0.1875 1.91 1.94 0.9811
C5H8O2 Acetylacetone 20 A 48 61 0.7847 9.40 6.91 1.3612 4.65 4.85 0.9589
C3H3N+ acrylonitrile cation 4 A' 2073 2632 0.7877 447.43 1644.43 0.2721 11.94 12.49 0.9559
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 33 A 66 83 0.7880 7.48 7.67 0.9752 2.53 2.81 0.8978
H2OH2CO water formaldehyde dimer 14 A 132 167 0.7883 123.06 114.73 1.0726 1.07 1.09 0.9891
H2OHCOOH Water formic acid dimer 2 2 A 88 112 0.7892 16.87 15.20 1.1097 5.50 6.56 0.8382
CuCH3 monomethyl copper 3 A1 573 724 0.7908 44.88 38.79 1.1569 4.10 3.51 1.1684
N2O+ Nitrous oxide cation 3 Π 509 643 0.7914 3.58 1.73 2.0712 14.24 14.23 1.0002
NH3NH3 Ammonia Dimer 13 Bg 112 141 0.7923 0.00 0.00   1.09 1.10 0.9935
SCN thiocyanato radical 1 Σ 2029 2560 0.7925 34.45 1.38 24.9512 12.80 12.87 0.9948
C4H8 cyclobutane 6 A1 202 254 0.7937 0.00 0.00   1.50 1.51 0.9932
CuF Copper monofluoride 1 Σ 665 836 0.7955 88.95 118.93 0.7479 22.67 22.67 1.0000
C5H8O2 Acetylacetone 39 B 56 70 0.7990 13.69 11.50 1.1901 3.86 3.99 0.9666
HSO3 HOSO2 4 A 915 1144 0.8005 241.57 60.61 3.9859 16.58 11.40 1.4547
H2OHCOOH Water formic acid dimer 2 4 A 162 203 0.8012 85.72 116.32 0.7370 1.57 1.12 1.3940
C4H9N Cyclobutylamine 21 A' 165 206 0.8022 1.57 2.10 0.7456 1.99 2.05 0.9679
CuCl Copper monochloride 1 Σ 382 474 0.8051 42.05 54.95 0.7652 41.57 41.57 1.0000
NO3 Nitrogen trioxide 6 B2 580 717 0.8078 10.83 32.91 0.3292 15.75 15.93 0.9886
H2OHCOOH Water formic acid dimer 1 17 A 88 109 0.8084 32.30 15.35 2.1041 5.37 6.93 0.7749
NF3- Nitrogen trifluoride anion 1 A1 714 882 0.8100 23.04 54.45 0.4230 15.91 16.58 0.9599
BrO Bromine monoxide 1 Σ 638 787 0.8107 2.55 4.40 0.5793 18.48 18.48 1.0000
HCOOHH2O Formic acid water dimer 15 A 247 304 0.8108 77.83 81.33 0.9570 1.20 1.14 1.0586
NO3 Nitrogen trioxide 5 B2 1915 2360 0.8113 831.62 2443.46 0.3403 14.62 14.46 1.0108
H2OHCOOH Water formic acid dimer 1 16 A 119 146 0.8127 6.91 0.42 16.3887 5.40 6.96 0.7749
BrCl+ bromine chloride cation 1 Σ 492 605 0.8130 19.00 40.13 0.4734 42.18 42.18 1.0000
C3O2 Carbon suboxide 7 Πu 86 106 0.8133 0.57 0.01 40.1972 13.28 13.29 0.9988
C3O2 Carbon suboxide 7 Πu 86 106 0.8133 0.57 0.01 40.1972 13.28 13.29 0.9988
HCN- Hydrogen cyanide anion 1 A' 2003 2459 0.8145 463.84 615.61 0.7535 1.40 6.64 0.2103
H2OHCOOH Water formic acid dimer 2 1 A 82 100 0.8145 15.96 14.46 1.1037 1.94 1.82 1.0608
C5H8 Cyclobutane, methylene- 19 A' 98 120 0.8177 0.02 0.13 0.1171 1.87 2.02 0.9262
C5H8 Cyclopentene 18 A' 150 183 0.8206 0.11 0.16 0.6898 1.60 1.60 1.0022
C2H2N4 sym-tetrazine 13 B2u 886 1079 0.8212 99.92 29.55 3.3820 13.25 3.62 3.6589
NH3NH3 Ammonia Dimer 6 Ag 127 154 0.8250 0.00 0.00   4.59 4.75 0.9677
HCCCN+ Cyanoacetylene cation 1 Σ 3510 4252 0.8255 201.13 4107.33 0.0490 1.13 7.75 0.1461
H2OHCOOH Water formic acid dimer 1 13 A 378 457 0.8276 234.86 261.45 0.8983 1.08 1.05 1.0219
NO2 Nitrogen dioxide 3 B2 1880 2271 0.8277 756.98 1966.06 0.3850 14.62 14.62 0.9995
C3H6O2 1,3-Dioxolane 9 A 1300 1569 0.8281 207.83 1.28 161.7819 2.61 1.09 2.3869
CO+ carbon monoxide cation 1 Σ 2392 2887 0.8287 4.48 629.15 0.0071 13.44 13.44 1.0000
CH2CHO Vinyloxy radical 4 A' 1614 1938 0.8329 10.39 308.50 0.0337 1.28 10.21 0.1251
C6F6 hexafluorobenzene 9 B2u 1206 1448 0.8331 0.00 0.00   12.00 12.00 1.0003
H2OH2CO water formaldehyde dimer 12 A 191 228 0.8353 27.62 40.91 0.6750 1.10 1.08 1.0130
H2OHCOOH Water formic acid dimer 1 18 A 64 77 0.8354 9.61 12.57 0.7643 2.03 2.02 1.0065
CP Carbon monophosphide 1 Σ 1011 1209 0.8362 2.36 28.77 0.0821 14.48 14.48 1.0000
C4H6S Thiophene, 2,3-dihydro- 27 A 158 189 0.8390 1.44 1.35 1.0683 1.99 2.00 0.9976
HCOOHH2O Formic acid water dimer 18 A 166 197 0.8400 7.98 8.41 0.9486 4.26 2.21 1.9290
C3H7NO Propanamide 27 A 276 328 0.8402 10.35 264.54 0.0391 3.30 1.25 2.6428
N2O+ Nitrous oxide cation 3 Π 421 500 0.8430 4.53 2.21 2.0500 14.24 14.23 1.0002
BeCl- beryllium monochloride anion 1 Σ 447 530 0.8432 124.77 90.88 1.3729 10.63 10.63 1.0000
H2OCH3OCH3 water dimethylether dimer 28 A 137 162 0.8440 99.81 108.96 0.9160 1.26 1.14 1.1090
H2OCH3OCH3 water dimethylether dimer 27 A 145 171 0.8463 30.94 17.52 1.7660 2.91 3.35 0.8686
HCCO ketenyl radical 2 A' 2092 2469 0.8475 89.18 1048.73 0.0850 9.10 11.73 0.7761
FHF- FHF- 2 Σu 1363 1608 0.8475 3073.70 2681.71 1.1462 1.03 1.03 1.0000
C5H5NO 3-Pyridinol 29 A" 300 354 0.8478 147.94 141.75 1.0437 1.22 1.11 1.0984
NH3NH3 Ammonia Dimer 10 Au 89 105 0.8493 28.36 31.80 0.8918 1.01 1.02 0.9989
C4H10O 1-Propanol, 2-methyl- 32 A 525 616 0.8517 6.59 4.04 1.6285 3.53 2.46 1.4375
H2OH2O water dimer 7 A' 182 213 0.8518 121.68 169.23 0.7190 3.39 3.16 1.0723
C3H6O2 1,3-Dioxolane 7 A 1377 1616 0.8522 9.02 6.36 1.4180 1.17 1.10 1.0613
C2H+ Ethynyl cation 2 Σ 1813 2124 0.8534 44.53 3.93 11.3308 6.49 5.32 1.2218
HCN- Hydrogen cyanide anion 3 A' 885 1033 0.8561 80.47 158.17 0.5087 1.29 1.24 1.0332
CS2+ Carbon disulfide cation 4 Πu 311 362 0.8569 0.66 2.07 0.3175 13.31 13.31 1.0000
C4H6OS 2,3-dihydrothiophene-2-ol 30 A 77 90 0.8577 2.09 1.76 1.1908 2.97 2.99 0.9931
C3+ carbon trimer cation 2 Σu 2496 2909 0.8580 3932.18 9050.54 0.4345 12.00 12.00 1.0000
C3H6O2 1,3-Dioxolane 8 A 1352 1575 0.8581 85.10 1.74 48.8520 1.32 1.11 1.1851
CS+ carbon monosulfide cation 1 Σ 1248 1454 0.8582 3.21 51.64 0.0622 14.47 14.47 1.0000
HCONH2CN2H4 formamide aminomethanimine dimer 28 A 197 229 0.8583 56.16 65.36 0.8593 3.81 3.83 0.9956
NaCl+ sodium chloride cation 1 Σ 137 159 0.8608 33.09 32.09 1.0310 26.60 26.60 1.0000
C6H5 phenyl 13 A2 404 469 0.8608 0.00 0.00   2.87 3.00 0.9598
HCCCN+ Cyanoacetylene cation 7 Π 224 260 0.8612 0.02 0.49 0.0329 5.33 5.42 0.9825
HCN+ hydrogen cyanide cation 1 Σ 3420 3971 0.8612 261.48 1.27 205.9242 1.17 4.27 0.2740
B2 Boron diatomic 1 Σg 971 1123 0.8643 0.00 0.00   11.01 11.01 1.0000
BF3+ boron trifluoride cation 3 E' 1974 2283 0.8644 2476.38 7743.21 0.3198 12.13 12.01 1.0099
BF3+ boron trifluoride cation 3 E' 1974 2283 0.8644 2476.38 7743.21 0.3198 12.13 12.01 1.0099
CH3OHH2O methanol water dimer 11 A' 267 309 0.8657 282.69 280.78 1.0068 1.41 1.35 1.0442
C3H6O2 1,3-Dioxolane 10 A 1267 1462 0.8665 31.94 9.21 3.4674 1.86 1.29 1.4437
HCOOHH2O Formic acid water dimer 16 A 218 251 0.8673 29.89 40.89 0.7310 6.55 6.41 1.0213
AlS Aluminum sulfide 1 Σ 615 707 0.8699 8.12 54.12 0.1501 29.06 29.06 1.0000
C3 carbon trimer 3 Πu 153 176 0.8700 2.13 20.17 0.1058 12.00 12.00 1.0000
C3 carbon trimer 3 Πu 153 176 0.8700 2.13 20.17 0.1058 12.00 12.00 1.0000
C6H12 Cyclohexane 25 A 121 139 0.8701 0.02 0.02 1.1823 1.72 1.71 1.0018
CH3OHH2O methanol water dimer 12 A' 162 186 0.8703 13.96 6.81 2.0513 3.63 3.87 0.9395
F3NO Nitrogen trifluoride oxide 1 A1 1665 1912 0.8707 682.51 516.25 1.3220 14.74 14.77 0.9979
CH3CN+ Acetonitrile cation 5 ?a 2222 2552 0.8707 81.27 321.93 0.2524 12.30 1.01 12.1881
C6H5 phenyl 12 A2 850 975 0.8720 0.00 0.00   1.25 1.25 1.0045
HCCCN+ Cyanoacetylene cation 7 Π 223 255 0.8731 0.22 0.42 0.5237 6.18 4.64 1.3325
Al2 Aluminum diatomic 1 Σg 316 362 0.8741 0.00 0.00   26.98 26.98 1.0000
NH2CSNH2 Thiourea 18 B 363 414 0.8762 549.25 1.93 285.2210 1.19 3.83 0.3108
HSO3 HOSO2 8 A 363 413 0.8781 15.04 16.56 0.9086 4.67 13.50 0.3457
H2OH2O water dimer 6 A' 384 436 0.8791 95.22 40.20 2.3686 1.10 1.08 1.0198
C2H3 vinyl 4 A' 1634 1858 0.8792 1.50 2.31 0.6476 1.50 5.76 0.2608
SCN thiocyanato radical 3 Π 359 408 0.8800 6.79 8.69 0.7805 12.77 12.77 1.0004
AlCl- aluminum monochloride anion 1 Σ 308 350 0.8803 115.35 94.52 1.2203 29.96 29.96 1.0000
C6H4F2 1,4-difluorobenzene 20 B2u 1276 1449 0.8803 0.66 0.24 2.7155 3.69 5.97 0.6186
H2OH2CO water formaldehyde dimer 13 A 174 197 0.8804 32.01 35.06 0.9132 4.12 4.38 0.9404
C6H5 phenyl 21 B2 1666 1892 0.8806 0.79 7.92 0.0994 3.69 8.44 0.4374
C4H6OS 4,5-dihydrothiophene-2-ol 30 A 156 177 0.8808 1.77 2.90 0.6108 2.39 2.75 0.8679
HCOOHH2O Formic acid water dimer 17 A 179 203 0.8813 52.74 25.96 2.0313 1.67 3.37 0.4967
C4H4N2 Pyrazine 17 B2u 1203 1365 0.8816 0.92 0.14 6.7198 2.18 7.73 0.2825
HCOOHH2O Formic acid water dimer 13 A 578 656 0.8819 244.33 170.20 1.4356 1.12 1.48 0.7604
NaF+ sodium fluoride cation 1 Σ 159 180 0.8824 20.93 22.97 0.9112 20.62 20.62 1.0000
H2ONH3 Water Ammonia Dimer 9 A' 185 209 0.8829 19.31 13.99 1.3803 2.66 3.26 0.8179
C6H5 phenyl 18 B1 436 493 0.8843 2.46 5.43 0.4535 3.58 3.74 0.9553
MgCl- magnesium monochloride anion 1 Σ 285 322 0.8853 74.21 53.39 1.3900 27.50 27.50 1.0000
H2OHCOOH Water formic acid dimer 2 3 A 155 175 0.8855 37.57 0.97 38.7329 2.39 7.08 0.3383
C3H7NO Propanamide 28 A 234 265 0.8856 6.52 9.25 0.7052 1.09 3.29 0.3316
CHOCH2OH hydroxy acetaldehyde 17 A" 349 393 0.8859 117.89 99.26 1.1877 1.18 1.14 1.0345
C4+ Carbon tetramer cation 3 Σu 1337 1509 0.8860 114.49 2250.05 0.0509 12.00 12.00 1.0000
CH3COCH3 Acetone 12 A2 54 61 0.8863 0.00 0.00   1.02 1.02 0.9994
H2OH2CO water formaldehyde dimer 10 A 524 591 0.8867 246.88 247.56 0.9972 1.06 1.05 1.0096
H2OH2O water dimer 11 A" 143 161 0.8875 155.14 183.58 0.8451 1.07 1.07 0.9969
C4H6OS 4,5-dihydrothiophene-3-ol 29 A 216 243 0.8877 146.66 42.24 3.4718 1.14 2.93 0.3886
HNS- HNS- 3 A' 774 871 0.8892 17.00 38.05 0.4468 13.34 14.64 0.9109
C2N2+ Cyanogen cation 4 Πg 571 641 0.8896 0.00 0.00   12.18 12.18 1.0001
H2OCH3OCH3 water dimethylether dimer 24 A 290 326 0.8899 80.87 89.87 0.8998 1.21 1.14 1.0683
NS- nitrogen sulfide anion 1 Σ 863 969 0.8902 50.85 52.62 0.9664 16.90 16.90 1.0000
C4H6OS 4,5-dihydrothiophene-3-ol 30 A 159 179 0.8907 9.14 8.62 1.0605 1.96 2.16 0.9087
C5H10O 3-Pentanone 21 A2 27 31 0.8912 0.00 0.00   1.59 1.58 1.0035
CH3OHH2O methanol water dimer 20 A" 90 101 0.8914 10.55 32.29 0.3266 1.02 1.03 0.9892
C2H3 vinyl 9 A" 886 993 0.8917 2.12 10.49 0.2018 1.27 1.27 1.0017
CH2OH Hydroxymethyl radical 9 A 412 462 0.8921 141.85 120.54 1.1768 1.08 1.08 0.9964
O3- Ozone anion 1 A1 1221 1368 0.8925 2.14 5.88 0.3645 15.99 15.99 1.0000
CCH2 vinylidene 4 B1 850 952 0.8927 37.78 36.86 1.0251 1.34 1.35 0.9935
H2OCH3OCH3 water dimethylether dimer 22 A 582 652 0.8927 177.07 183.03 0.9674 1.04 1.04 1.0028
C6H5 phenyl 4 A1 1639 1836 0.8928 0.69 2.37 0.2895 2.88 7.51 0.3842
LiCl+ lithium chloride cation 1 Σ 286 320 0.8929 140.43 134.97 1.0405 8.10 8.10 1.0000
C4H8O Cyclobutanol 20 A' 190 213 0.8954 1.99 2.28 0.8716 1.99 2.07 0.9628
C4H8O2 1,3-Dioxolane, 2-methyl- 35 A 215 240 0.8957 3.77 2.17 1.7395 1.95 1.39 1.4090
NH3NH3 Ammonia Dimer 5 Ag 444 495 0.8972 0.00 0.00   1.09 1.10 0.9935
HCCO ketenyl radical 4 A' 619 690 0.8973 2.10 158.86 0.0132 4.01 1.30 3.0932
NH3NH3 Ammonia Dimer 9 Au 236 263 0.8975 139.57 132.46 1.0537 1.04 1.04 0.9997
BH3NH3 borane ammonia 5 A1 605 673 0.8982 34.64 14.32 2.4183 4.97 4.72 1.0517
C6H5 phenyl 15 B1 920 1024 0.8986 0.75 0.73 1.0183 1.32 1.28 1.0339
PO2 Phosphorus dioxide 3 B2 1457 1620 0.8993 146.57 379.92 0.3858 20.67 20.71 0.9980
C2H3 vinyl 8 A" 958 1064 0.8999 70.31 87.63 0.8023 1.19 1.21 0.9820