return to home page

XIII.F.2. (III.B.7.b.) (IV.C.7.) (XVIII.B.2.)

Bad vibrational frequency predictions

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 HF/aug-cc-pVQZ
Calculated values were scaled by 0.9085.

Species Name mode Symmetry Experiment Theory difference ratio
C2H2N4 sym-tetrazine 18 B3u 254 369 115 0.687
COBr2 Carbonic dibromide 4 B1 757 526 -231 1.439
COBr2 Carbonic dibromide 6 B2 512 359 -153 1.425
CH2D2 methane-d2 6 B1 3013 2184 -829 1.380
CH2D2 methane-d2 8 B2 2234 2949 715 0.758
C2H5 Ethyl radical 9 A' 528 426 -102 1.241
C2H+ Ethynyl cation 3 Π 550 855 306 0.643
CH3 Methyl radical 2 A2" 606 377 -229 1.607
CH3 Methyl radical 2 A2" 606 377 -229 1.607
CH3 Methyl radical 2 A2" 606 377 -229 1.607
CH3 Methyl radical 2 A2" 606 377 -229 1.607
CH2OH Hydroxymethyl radical 8 A 482 693 211 0.695
CH2OH Hydroxymethyl radical 9 A 234 365 131 0.642
C2H3+ vinyl cation 2 A1 2217 2893 676 0.766
C2H Ethynyl radical 3 Π 372 555 184 0.669
C2Cl2+ dichloroacetylene cation 5 Πu 233 191 -42 1.218
NS Mononitrogen monosulfide 1 Σ 1219 851 -367 1.432
SiN Silicon nitride 1 Σ 1151 880 -271 1.308
PS phosphorus sulfide 1 Σ 739 495 -244 1.493
CP Carbon monophosphide 1 Σ 1240 928 -312 1.336
C2Cl2+ dichloroacetylene cation 4 Πg 318 460 142 0.691
AlO Aluminum monoxide 1 Σ 979 727 -252 1.347
SiH- silicon monohydride anion 1 Σ 2175 1755 -420 1.240
SiH- silicon monohydride anion 1 Σ 2175 1755 -420 1.240
SiH- silicon monohydride anion 1 Σ 2175 1755 -420 1.240
SiH- silicon monohydride anion 1 Σ 2175 1755 -420 1.240
H3O+ hydronium 2 A1 954 760 -195 1.256
H2POH Phosphinous acid 9 A" 375 260 -115 1.444
PN+ phosphorus nitride cation 1 Σ 1200 764 -436 1.571
GeH2 germylene 1 A1 1856 922 -934 2.013
Mg2 Magnesium diatomic 1 Σg 51 2 -49 20.755
NNS Nitrogen sulfide 2 Σ 752 551 -201 1.366