We propose a thermodynamically consistent model involving detailed screened ions, described by superconfigurations, in plasmas. In the present work, the electrons, bound and free, are treated quantum-mechanically so that resonances are carefully taken into account in the self-consistent calculation of the electronic structure of each superconfiguration. The procedure is in some sense similar to the one used in Inferno code developed by D.A. Liberman; however, here we perform this calculation in the ion-sphere model for each superconfiguration. The superconfiguration approximation allows rapid calculation of necessary averages over all possible configurations representing excited states of bound electrons. The model enables a fully quantum-mechanical self-consistent calculation of the electronic structure of ions and provides the relevant thermodynamic quantities (e.g., internal energy, Helmholtz free energy and pressure), together with an improved treatment of pressure ionization. It should therefore give a better insight into the impact of plasma effects on photoabsorption spectra.