National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities
NIST policy on privacy, security, and accessibility.
© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

return to home page

III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for C4H4N (pyrrolide 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)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A1 A1   3096 3126 -29.8 0.990   1.108 1.107 0.001 1.001   3.08 0.46 2.62 6.723
2 A1 A1   3065 3092 -26.7 0.991   1.095 1.097 -0.002 0.998   6.77 1.01 5.76 6.717
3 A1 A1   1548 1523 24.9 1.016   4.253 3.565 0.689 1.193   0.22 11.42 -11.19 0.019
4 A1 A1   1426 1394 32.0 1.023   3.013 4.843 -1.829 0.622   22.98 28.80 -5.82 0.798
5 A1 A1   1145 1204 -58.2 0.952   1.916 2.415 -0.499 0.793   0.29 12.40 -12.10 0.024
6 A1 A1   1067 1067 -0.8 0.999   1.380 1.759 -0.379 0.785   28.78 40.46 -11.68 0.711
7 A1 A1   985 1039 -53.8 0.948   2.331 1.354 0.977 1.722   1.40 3.41 -2.01 0.410
8 A1 A1   848 848 -0.3 1.000   5.587 4.671 0.916 1.196   13.15 12.72 0.42 1.033
9 A2 A2   940 836 103.7 1.124   1.331 1.522 -0.191 0.874   0.00 0.00 0.00  
10 A2 A2   783 778 4.6 1.006   1.540 1.182 0.358 1.303   0.00 0.00 0.00  
11 A2 A2   502 470 31.6 1.067   2.245 2.923 -0.678 0.768   0.00 0.00 0.00  
12 B1 B1   794 833 -38.3 0.954   1.589 1.770 -0.181 0.898   12.78 0.09 12.69 141.669
13 B1 B1   706 670 36.6 1.055   1.195 1.161 0.033 1.029   59.99 58.98 1.02 1.017
14 B1 B1   532 537 -4.6 0.991   2.436 2.221 0.215 1.097   20.22 31.03 -10.81 0.652
15 B2 B2   3076 55404 -52328.2 0.056   1.090 12.187 -11.097 0.089   25.25 0.00 25.25  
16 B2 B2   3061 3105 -44.5 0.986   1.089 1.086 0.003 1.003   23.81 56.30 -32.48 0.423
17 B2 B2   1316 3085 -1768.7 0.427   1.735 1.088 0.646 1.594   68.88 77.77 -8.88 0.886
18 B2 B2   1262 1270 -7.7 0.994   1.197 1.782 -0.586 0.671   21.57 104.15 -82.58 0.207
19 B2 B2   1004 1251 -247.1 0.803   2.839 1.216 1.624 2.336   0.68 43.04 -42.36 0.016
20 B2 B2   870 987 -117.6 0.881   3.437 2.209 1.229 1.556   0.72 2.80 -2.08 0.256
21 B2 B2   877i 847 -1724.8 -1.035   10.779 4.457 6.322 2.418   802.90 7.00 795.90 114.716
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.