Direct-potential-fit analysis for the A3Π1u-X1Σg+ system of Br2

► 9334 New Br2 (A-X) laser absorption measurements spanning v(X) = 2-8 and v(A) = 2-16. ► 2992 New magnetic rotation Br2 (A-X) transitions for v(X) = 0-2 → v(A) = 13-37. ► A direct potential-fit (DPF) analysis yields accurate, fully analytic potential energy functions for both states. ► The A-X electronic isotope shift is Te81,81-Te79,79=-0.016(3)cm-1. ► An improved ground-state well depth is De(X)=15894.495(2)cm-1.