Dear Kai,
Thank you for interested in Mass++.
I am Satoshi Tanaka, one of developers of Mass++
at Shimadzu Corporation.
I'd like to answer your question.
Mass++ does not have peak width
but has peak start and end.
You can confirm these information by the peak list pane.
([View] > [Pane] > [Peak List])
If you want to calculate FWHM (full width at half maximum)
or HWHM (half width at half maximum),
these information is not enough and it's necessary to access
data by program coding such as plug-in development.
It's a little difficult because we don't have enough documents
and samples. But it's possible.
If you have some questions, please let us know them.
regards,
--
Saotshi Tanaka