When you open the peak fitting window, if the selected spectrum is an emission with a spin-orbit pair (or the box next to ‘Add Doublet’ is input with a spin-orbit coupled doublet label, e.g. Ag3d), you have the option to add a pair of peaks.

Avantage by default includes peak fitting constraints relevant to spin-orbit peak properties, meaning you don’t need to remember the parameters for the different orbitals! Simply click add doublet, and check the peak properties in the fitting table.

FWHM constraints default to 1:1, since for the vast majority of spin-orbit doublets the core-hole lifetime should be identical, and therefore the peak widths are the same. In certain examples however, this is not the case, and we must change this constraint. For example, in TiO2 we can adjust our default constraint to A * 1 (+- 1.1) and hit enter, to allow the FWHM constraint to vary between a range of energies.

By default, Avantage constraints the peak size based on height. You can change this by deleting the constraint in the peak height box, and inputting a new constraint into the area column. This may be more useful for systems with uneven heights, such as those found in Coster-Kronig broadening doublets.

In the Peak BE column, the constraint row can be modified to specify the splitting energy between peaks based on literature data. This can also be modified in the form of X + ### (+ Y, – Z) – e.g. A + 5.7 (+0.3, -0.2) will put the second peak between 5.5 and 6 eV higher than peak A.

X = Peak label to reference to

### = Energy splitting

Y = Upper limit

Z = Lower limit