The window for the cross peak catalog has previously been shown as an example of a window containing a browser. However, as this window has many interesting facilities, we will now take a closer look at it.
The default (i.e. without changing anything) cross peak catalog is shown in Figure 1. The peaks are sorted according to the order in which they are entered in the catalog, either manually or automatically. You can sort the peaks according to any of the chemical shift values by pressing the Sort 1, Sort 2, etc. buttons. Pressing Sort ID brings you back to having the peaks sorted according to the identifier number. The field to the right of the Lookup CP button can be filled with a value. If the Sort ID is selected, an integer must be placed here, but a peak at a certain chemical shift value on one axis can be located by selecting the axis for the Sort button, enter the chemical shift value in the field, and pressing the Lookup CP button. Note, for this field the normal editor is not used, so you don't have to click the mouse in this window before entering a value.
You can select one of the peaks in the list by pressing the left mousebutton when the mouse cursor is on the peak to be studied. If the same peak is shown in a contouring window, the marker of that peak (if plotted) will change into thick lines. If you move up or down in the peak list using the arrow buttons and want to go back to the focused peak, press the See focus button.
The Delete button deletes the currently selected peak, including all references to it from atoms. The Delete All button deletes all the peaks selected for display. This is not so interesting if no search pattern has been set up, as it will remove all peaks in your database. When the Delete All button is pressed, you will be asked twice to confirm the deletion. If you answer yes the first time, the program will count the number of peaks to delete, and ask if you really want to delete xxx peaks from the database. If you answer no in this case, you can use this facility to count the number of peaks in your database non-destructively.
The Setup button opens up a setup window used to select a subset of the cross peak catalog to be displayed in this window. The window contains three filters: One that limits the peaks according to one or more chemical shift value ranges, one that limits the peaks to be peaks from one or more specific spectra, and one that limits the peaks displayed according to the degree of assignment that peak has. A few examples of how to use this window will be given below.
The setup shown in Figure 2 will limit the display to show only cross peaks from the spectrum named DQFCOSY. One or more spectra can be added to the list at the bottom of the window. When Update is pressed, the result can be viewed in the cross peak catalog window.
The result of the filter displayed in Figure 2 can be shown in Figure 3. Note: Pressing the Count button counts the total amount of cross peaks selected by the filter.
The filter shown in Figure 4 contains an example of using all three filter types: The chemical shift values are limited to a range where HN-HA peaks normally occur, the peak must be located in the spectrum named COSY, and the peak must have been assigned to atoms that have been used in a spin system.
The result of pressing Update in the window in Figure 4 is shown in Figure 5.
Note, some filters may take a long time to execute, especially assignment filters, as many database operations are necessary to determine the degree of assignment of a cross peak.
The Delete All button is a very useful tool together with the cross peak filter: For instance, it can be used to remove cross peaks located by the automatic cross peak identifier in a noisy area, e.g. in the water signal: Simply select the range to remove in the Chem. Shift Ranges list, select Range instead of Full, Update the cross peak catalog display, press Delete All, and press YES in both confirmation windows.