Direct <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>Q</mml:mi></mml:mrow></mml:math> -Value Determination of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>β</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> Decay of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Re</mml:mi></mml:mrow><mml:mprescripts /><mml:none /><mml:mrow><…

The cyclotron frequency ratio of $^{187}\mathrm{Os}^{29+}$ to $^{187}\mathrm{Re}^{29+}$ ions was measured with the Penning-trap mass spectrometer PENTATRAP. achieved result $R=1.000\:000\:013\:882(5)$ is date most precise such measurement performed on ions. Furthermore, total binding-energy difference 29 missing electrons in Re and Os calculated by relativistic multiconfiguration methods, yielding value $\Delta E = 53.5(10)$ eV. Finally, using results, between neutral $^{187}$Re $^{187}$Os, i.e., $Q$ $\beta^-$ decay $^{187}$Re, determined be 2470.9(13)