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Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
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III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for H2OHCOOH (Water formic acid dimer 1)

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)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A A   3757 3674 83.1 1.023   1.083 1.081 0.002 1.002   93.76 79.22 14.54 1.184
2 A A   3654 3547 106.7 1.030   1.046 1.046 0.000 1.000   26.42 21.89 4.53 1.207
3 A A   3629 3474 155.2 1.045   1.065 1.064 0.001 1.001   113.57 74.52 39.04 1.524
4 A A   3019 3022 -2.5 0.999   1.099 1.097 0.002 1.002   17.98 8.98 8.99 2.001
5 A A   1827 1731 95.2 1.055   7.765 7.551 0.214 1.028   449.62 257.77 191.85 1.744
6 A A   1644 1645 -0.6 1.000   1.081 1.081 -0.000 1.000   111.94 83.59 28.35 1.339
7 A A   1393 1356 37.4 1.028   1.151 1.131 0.020 1.018   16.87 8.91 7.96 1.893
8 A A   1280 1237 43.3 1.035   1.650 1.645 0.005 1.003   11.71 4.25 7.46 2.756
9 A A   1134 1072 62.3 1.058   3.585 3.780 -0.195 0.948   320.40 289.20 31.20 1.108
10 A A   1081 1023 58.2 1.057   1.584 1.501 0.083 1.055   1.20 3.51 -2.31 0.341
11 A A   638 657 -19.1 0.971   1.238 1.274 -0.037 0.971   211.53 173.37 38.15 1.220
12 A A   622 590 32.3 1.055   3.443 3.468 -0.025 0.993   63.52 49.63 13.89 1.280
13 A A   340 431 -91.1 0.789   1.078 1.055 0.023 1.022   234.86 261.56 -26.70 0.898
14 A A   194 214 -20.0 0.907   1.133 1.158 -0.025 0.978   144.87 124.90 19.97 1.160
15 A A   121 164 -43.7 0.734   1.125 1.045 0.080 1.076   92.56 96.13 -3.58 0.963
16 A A   107 138 -31.2 0.774   5.396 6.958 -1.563 0.775   6.91 0.42 6.49 16.455
17 A A   79 103 -23.7 0.770   5.366 6.924 -1.558 0.775   32.30 15.30 17.00 2.111
18 A A   58 73 -14.9 0.795   2.029 2.016 0.013 1.006   9.61 12.58 -2.97 0.764
scaled by     0.8985 0.943

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.