  Employing a 10-orbital tight binding model, we present a new set of hopping
parameters fitted directly to our latest high resolution angle-resolved
photoemission spectroscopy (ARPES) data for the high temperature tetragonal
phase of FeSe. Using these parameters we predict a large 10 meV shift of the
chemical potential as a function of temperature. In order to confirm this large
temperature dependence, we performed ARPES experiments on FeSe and observed a
$\sim$25 meV rigid shift to the chemical potential between 100 K and 300 K.
This unexpectedly strong shift has important implications for theoretical
models of superconductivity and of nematic order in FeSe materials.
