“…Several adequate models have been proposed not only for plasma-like media (metals, doped semiconductors, electrolyte solutions) [29,37,53,[77][78][79] but also for media with bound electrons (insulators, intrinsic semiconductors) [80][81][82][83]. The quantum-mechanical character of ( ) ε k [84,85] was shown to be important in surface problems [25,27,32,33,86]. However, the main features of the nonlocal electrostatics can be understood on the basis of the simple quasi-classical models based on the Pauli principle and applied to metals [78,87] or semiconductors [80,81].…”