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Compare vibrational frequencies for two calculations for CH2CHO (Vinyloxy radical)


A = HF/6-31G*
B = MP2/6-31G*

scale factors=0.8985, 0.943
  symmetry   frequency (cm-1)   reduced mass (amu)   IR Intensity (km mol-1)   Raman Activity (Å4/u)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A' A'   3101 3181 -80.0 0.975   1.121 1.122 -0.001 0.999   5.87 1.44 4.42 4.061          
2 A' A'   3004 3059 -54.9 0.982   1.054 1.051 0.003 1.003   4.89 2.11 2.78 2.315          
3 A' A'   2919 2818 101.6 1.036   1.086 1.089 -0.003 0.997   66.89 116.61 -49.72 0.574          
4 A' A'   1450 1825 -374.4 0.795   1.277 10.207 -8.929 0.125   10.39 305.54 -295.15 0.034          
5 A' A'   1400 1424 -23.8 0.983   1.259 1.218 0.041 1.034   6.86 13.90 -7.04 0.493          
6 A' A'   1272 1386 -114.2 0.918   4.091 1.144 2.947 3.576   15.01 7.31 7.70 2.054          
7 A' A'   1096 1094 2.0 1.002   3.096 2.475 0.620 1.251   16.12 57.76 -41.65 0.279          
8 A' A'   953 911 42.3 1.046   1.789 2.023 -0.234 0.884   3.00 9.79 -6.79 0.307          
9 A' A'   485 482 3.7 1.008   2.452 2.386 0.066 1.028   15.02 15.59 -0.56 0.964          
10 A" A"   915 1016 -100.9 0.901   1.496 1.670 -0.174 0.896   0.06 5.85 -5.78 0.011          
11 A" A"   709 634 75.0 1.118   1.259 1.243 0.016 1.013   47.17 46.14 1.03 1.022          
12 A" A"   477 350 127.7 1.365   1.212 1.151 0.060 1.053   0.84 1.16 -0.32 0.722          
scaled by     0.8985 0.943
19 08 20 15 07

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.