Early Inner Detector Tracking Performance in the 2015 data at $\sqrt s$ = 13 TeV

This note summarises the studies undertaken to recommend benchmark values and systematic uncertainties for various aspects of the ATLAS Inner Detector tracking based on $\sqrt{s}= 13$ TeV proton-proton collisions from the Large Hadron Collider Run 2 data. The track reconstruction efficiency, fake rate, and related systematic uncertainties are presented for two different track quality selections, along with the impact parameter resolution and the alignment weak mode systematic uncertainities. These recommendations apply to physics analyses using Inner Detector tracks in Run 2 data and are important inputs for other objects based on tracks.