Michigan State University was awarded a $456,134 Project Grant from the National Science Foundation under the Geosciences (47.050) federal grant program. The university will conduct research and experiments to determine the dominant lower-mantle host phase for sodium and the seismic properties of sodium-bearing lower mantle materials. Laser-heated diamond anvil cell experiments and complementary density functional theory calculations will measure sodium concentration in (Mg,Fe)O ferropericlase under lower mantle conditions. The research aims to improve constraints on high-pressure mineralogy of sodium to update geophysical and thermodynamic modeling of the mantle's composition and heterogeneity. Additional outcomes include graduate and undergraduate student training and public outreach exhibits at the MSU Museum on salt geology and crystal structures. The three-year award period runs from August 15, 2023 through July 31, 2026.