Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology Home All data for one species Geometry Experimental Calculated Comparisons Bad Calculations Tutorials and Explanations Vibrations Experimental Calculated Scale factors Reactions Entropies Ions List Ions Energy Electron Affinity Proton Affinity Ionization changes point group Experimental One molecule all properties One property a few molecules Geometry Vibrations Energy Electrostatics Reference Data Calculated Energy Optimized Reaction Internal Rotation Orbital Nuclear repulsion energy Correlation Ion Excited State Basis Set Extrapolation Geometry Vibrations Frequencies Zero point energy (ZPE) Scale Factors Bad Calculations Electrostatics Charges Dipole Quadrupole Polarizability Spin Entropy and Heat Capacity Reaction Lookup by property Comparisons Geometry Vibrations Energy Entropy Electrostatics Ion Resources Info on Results Calculations Done Basis functions used I/O files Glossary Conversion Forms Links NIST Links External links Thermochemistry Tutorials Vibrations Entropy Energy Electrostatics Geometry Cost Bad Calculations FAQ Help Units Choose Units Explanations Credits Just show me Summary Using List Recent molecules Molecules Geometry Vibrations Energy Similar molecules Ions, Dipoles, etc. Index of CCCBDB Feedback You are here: Comparisons > Vibrations > Vibrations > 2 calculations

# Compare vibrational frequencies for two calculations for CH2F (fluoromethyl radical)

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

scale factors=0.8985, 0.943 0.247 5.059 -4.868 -0.144
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'   775 3036 -2261.5 0.255   1.288 1.041 1.237   14.37 13.50 1.065
2 A' A'   1141 1457 -315.8 0.783   6.208 1.149 5.405   132.03 9.87 13.383
3 A" A'   1151 1137 13.8 1.012   1.218 6.086 0.200   12.33 102.51 0.120
4 A' A'   1452 727 725.6 1.998   1.146 1.289 0.889   15.33 25.77 0.595
5 A' A"   2981 3181 -200.4 0.937   1.042 1.129 -0.087 0.923   17.15 19.81 0.866
6 A" A"   3107 1144 1963.5 2.717   1.127 1.219 -0.091 0.925   32.40 7.23 4.482
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.