Dear SIESTA users and developers, I have a question about the SimulateDoping option.
The manual says: "This option instructs the program to add a background charge density to simulate doping. The new “doping” routine calculates the net charge of the system, and adds a compensating background charge that makes the system neutral." As I understand, SIESTA (or any code) always (with or without this option) adds a compensating background charge density for charged cells - otherwise charged systems would have an infinite positive or negative charge. Then, what is the effect of SimulateDoping? We have done calculations of charged cells (slab+adsorbate) with and without the SimulateDoping option. The results (projected density of states) are somewhat different, but neither of them look physically meaningless. Is this option applicable to slab+adsorbate systems, where the charge is believed to be on the adsorbate? I hope that someone can explain this or refer me to some papers. Best regards, Natalia
