Accurate diffusion coefficients for dense white dwarf plasma mixtures

Diffusion coefficients are essential microphysics input for modeling white dwarf evolution, as they impact phase separation at crystallization and sedimentary heat sources. Present schemes computing diffusion accurate weak coupling ($\Gamma \ll 1$), but have errors large a factor of two in the strongly coupled liquid regime ($1 \lesssim \Gamma 200$). With modern molecular dynamics codes it is possible to accurately determine select systems with percent-level precision. In this work, we develop theoretically motivated law which works across wide range parameters typical interiors. We perform simulations pure mixtures that respectively model typical-mass C/O higher-mass O/Ne dwarf, resolve several trace neutron-rich nuclides. fit propose physically generalization mixtures. show roughly 15% when compared many individual elements under conditions dwarfs, straightforward implement stellar evolution codes.