I want to position my main window at start up.

It appears QDesktopWidget().screenGeometry() returns a QRect().

This appears to only have the width of one monitor of the virtual desktop (this is on Linux). In this particular set of hardware that's 0,0,1920,1080.

I can see with .screenCount that there are two monitors and .screenGeometry(x) returns the QRect of the associated screen (i.e. x = 0 or x = 1)

This is a QDialog set geometry will size the dialog, but, I don't see how to get it onto a specific screen (i.e. 0 or 1)

Confuse.