## IV.C.1. (XIII.D.1.) |

# Compare vibrational frequencies in CCCBDB for C_{4}N_{2} (2-Butynedinitrile)

### HF/CEP-31G

Frequency in cm^{-1}

Calculated | Experimental | |||||
---|---|---|---|---|---|---|

Mode Number | Symmetry | Frequency | diff | Symmetry | Frequency | Comment |

1 | Σ_{g} |
2402 | 112 |
Σ_{g} |
2290 | |

2 | Σ_{g} |
2155 | 36 |
Σ_{g} |
2119 | |

3 | Σ_{g} |
573 | -119 |
Σ_{g} |
692 | |

4 | Σ_{u} |
2292 | 51 |
Σ_{u} |
2241 | |

5 | Σ_{u} |
1098 | -56 |
Σ_{u} |
1154 | |

6 | Π_{g} |
449 | -55 |
Π_{g} |
504 | |

7 | Π_{g} |
150 | -113 |
Π_{g} |
263 | |

8 | Π_{u} |
496 | 24 |
Π_{u} |
472 | |

9 | Π_{u} |
111 | 4 |
Π_{u} |
107 |

See section **XIII.C.3** List or set vibrational scaling factors to change the scale factors used here.

See section **III.B.3.c** Calculate a vibrational scaling factor for a set of molecules to determine the least squares best scaling factor.

See section **III.B.3.b** List of vibrational scaling factors and their uncertainties for information on where the above scaling factor is from.