Dataset for: Extending the low-Z "border" of the A=100 region of deformation with precision mass spectrometry of 96-98Kr

The onset of collective nuclear behavior in the N=60, A~100, region is examined through high-precision mass measurements of 96-98Kr, performed with the ISOLTRAP mass spectrometer at ISOLDE, CERN.Our results for 96-97Kr agree with previous measurements, with our new 97Kr Penning-trap mass value three times more precise.The mass value of 98Kr is measured for the first time. The new mass surface, together with comparisons to beyond-mean-field theoretical predictions, suggests that collectivity persists for the Z=36 isotopes, blurring the apparent "low-$Z$ boundary" of this deformed region.