Observed Wavenumbers
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Dialog Box: Observed Wavenumbers [Input menu; Species dialog]

This dialog allows input of observed wavenumbers, for least-square adjustment or just for comparison. You must know, or be able to guess, the assignment of frequencies to species.

Isotope Configurations spin control. You can enter wavenumbers for up to three Isotope Configurations. The base configuration is number 1. If most frequencies are identical to those of the main configuration you can write a file (which contains all frequencies) and read it back for the other configuration(s), then change individual frequencies as necessary.

Individual modes can be omitted from any least-squares adjustment of forces. Modes with zero frequency, either observed or calculated, are never included in least-squares.

The observed wavenumbers are entered in descending order within each species. If a mode is not observed, its place must be taken by a value of 0.0 - the number of observed frequencies entered for each species should correspond with the theoretical number. This number should appear at the top of the dialog, but it will be valid only if a calculation has already been carried out. This can be done with the Symmetry only box in the Control window checked. The number of modes in each species appears in the Output window, and also can be seen in the Species dialog (Input menu).

The Act on Selected Row group allows you to insert or delete rows (observed values) and move them up or down, keeping the other observed values.

The All and None buttons after Least-squares turn all the least-squares flags, for this species only, on or off.

You can read the observed values from a text file. In this file, each wavenumber must be proceeded by the species number (species in the sequence as in the Species dialog, Input menu). This is best done with a species number and a wavenumber on each line, although line breaks are ignored in the file. The wavenumbers must be given in decreasing order for each species, and with 0.0 in the place of any missing frequencies.