New Nuclear Magnetic Moment of Bi209 : Resolving the Bismuth Hyperfine Puzzle
A recent measurement of the hyperfine splitting in the ground state of Li-like ${^{208}\mathrm{Bi}}^{80+}$ has established a ``hyperfine puzzle''---the experimental result exhibits a $7\ensuremath{\sigma}$ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017); J. P. Karr, Nat. Phys. 13, 533 (2017)]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (${\ensuremath{\mu}}_{I}$) of $^{209}\mathrm{Bi}$. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of ${\ensuremath{\mu}}_{I}(^{209…
[Be(ND 3 ) 4 ]Cl 2 : Synthesis, Characterisation and Space‐Group Determination Guided by Solid‐State Quantum Chemical Calculations
Treatment of BeCl2 with dry liquid ND3 and subsequent removal of the solvent leads to the colourless microcrystalline powder of [Be(ND3)4]Cl2. It crystallises in the orthorhombic space group Pna21 with a = 9.395(4), b = 11.901(6), c = 6.761(3) A, V = 755.9(6) and Z = 4 at 27 °C, and a = 9.3736(8), b = 11.8162(12), c = 6.6596(6) A, V = 737.62(12) and Z = 4 at –269.6 °C. The structure contains the tetrahedral tetraammineberyllium(II) cation which follows the octet rule. It was shown to be stable under ambient conditions and temperatures up to approximately 175 °C. We additionally discuss the aid of solid-state quantum chemical calculations for the assignment of proper crystallographic space g…