  PtSe$_2$ is one of the most promising materials for the next generation of
piezoresistive sensors. However, the large-scale synthesis of homogeneous thin
films with reproducible electromechanical properties is challenging due to
polycrystallinity. We show that stacking phases other than the AA-stacking in
the 1T phase become thermodynamically available at elevated temperatures. We
show that these can make up a significant fraction in a polycrystalline thin
film and discuss methods to characterize these stacking phases. Lastly, we
estimate their gauge factors, which vary strongly and significantly impact the
performance of a nanoelectromechanical device.
