Peaks are added to the peak list by clicking on a data point in the pattern. Note that when the plot is in zoom or pan mode (selected by the button with perpendicular arrows or the magnifying glass at the lower left), mouse clicks are not available to GSAS-II and peaks are not added. When a peak is added, a vertical line is drawn at the peak position. Right-clicking on a peak deletes it. Peaks can be moved by dragging them – press the mouse button down at the location of the vertical line and move the mouse to the new location for the peak while holding the mouse button down. Note that to drag a peak, click on a part of the line away from any data points. If you click on a point, you will add an additional peak.
If a peak is selected in the table in the data window, which can be done by double-clicking on the number to the left of the peak values, the corresponding vertical line is highlighted. The “d” and “u” keyboard keys, when pressed with the plot window active, will move successively through the peak table, selecting each peak in turn (downwards with “d” and upwards with “u”).
Peaks may added by reading them from a file. Use the “Peak List”/“Load Peaks...” menu command to read peaks from a file saved with the “Peak List”/“Save Peaks...” menu command. Do not use the Import/“Read powder pattern peaks” menu command. That is used for a different type of histogram that only has peaks, and does not have an associated powder pattern.