Magnetic Susceptibility of ReF6

The magnetic susceptibility of ReF₆ has been measured in the range 4°—296°K using the Faraday method. The susceptibility in the range 14°—296°K can be expressed by means of $${}_M{\chi }_{{\mathrm{ReF}}_6}{\text{=(78±1)×10}}^{\text{−4}}{\text{/T+(0.87±0.03)×10}}^{\text{−4}},$$ from which one calculates a moment of 0.25 Bohr magnetons. Applying a theory developed for gaseous ReF₆ [W. Moffitt, G. L. Goodman, M. Fred, and B. Weinstock, Mol. Phys. 2, 109 (1959)] to the magnetic measurements reported here gives ζ=3160 cm^—1 and 10Dq/α=55 000 cm^—1, where α is an orbital reduction parameter connecting the dl_2g and de_g levels. The diamagnetic susceptibility of WF₆ has been remeasured and preliminary measurements on TcF₆ are reported.