A new quotidian equation of state (QEOS) for hot dense matter

The quotidian equation of state (QEOS) is a general‐purpose equation of state model for use in hydrodynamic simulation of high‐pressure phenomena. Electronic properties are obtained from a modified Thomas–Fermi statistical model, while ion thermal motion is described by a multiphase equation of state combining Debye, Gruneisen, Lindemann, and fluid‐scaling laws. The theory gives smooth and usable predictions for ionization state, pressure, energy, entropy, and Helmholtz free energy. When necessary, the results may be modified by a temperature‐dependent pressure multiplier which greatly extends the class of materials that can be treated with reasonable accuracy. In this paper a comprehensive evaluation of the resulting thermodynamic data is given including comparison with other theories and shock‐wave data.