Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a 6LiD target. The data were taken at 160 GeV beam energy and the results are shown for the kinematic range View the MathML source in photon virtuality, 0.004<x<0.7 in the Bjorken scaling variable and View the MathML source in the mass of the hadronic final state. The deuteron double-spin asymmetry View the MathML source and the deuteron longitudinal-spin structure function View the MathML source are presented in bins of x and Q2. Towards lowest accessible values of x , View the MathML source decreases and becomes consistent with zero within uncertainties. The presented final View the MathML source values together with the recently published final View the MathML source values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the g1 world data at next-to-leading order of the strong coupling constant. In both cases, changes in central values of the resulting numbers are well within statistical uncertainties. The flavour-singlet axial charge a0, which is identified in the View the MathML source renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted at next-to-leading order accuracy from only the COMPASS deuteron data: View the MathML source. Together with the recent results on the proton spin structure function View the MathML source, the results on View the MathML source constitute the COMPASS legacy on the measurements of g1 through inclusive spin-dependent deep inelastic scattering.
