Carrier concentration 13 Electronic density of states 13 Electron density measurement 12 Electrons 7 Mathematical models 6 Ionosphere 5 Molecular dynamics 5 electron density 5 Approximation theory 4 Cassini 4 Chemical bonds 4 Electron density 4 Electron temperature 4 Electronic structure 4 Ions 4 Phase transitions 4 Topology 4 Atmospheric pressure 3 Atomic physics 3 Atoms 3 Band structure 3 Calculations 3 Electron densities 3 Electronic density 3 Ionization 3 Ionospheric electron densities 3 Molecular systems 3 Plasma jets 3 Poisson equation 3 Probes 3