  Predicting the charged particle transport properties of warm dense matter /
hot dense plasma mixtures is a challenge for analytical models. High accuracy
ab initio methods are more computationally expensive, but can provide critical
insight by explicitly simulating mixtures. In this work, we investigate the
transport properties and optical response of warm dense carbon-hydrogen
mixtures at varying concentrations under either conserved electronic pressure
or mass density at a constant temperature. We compare options for mixing the
calculated pure species properties to estimate the results of the mixtures. We
find that a combination of the Drude model with the Matthiessen's rule works
well for DC electron transport and low frequency optical response. This breaks
down at higher frequencies, where a volumetric mix of pure-species AC
conductivities works better.
