How to get the un-scf electron density ?

[fangyongxinxi]

Dear Sir,

1.
I am not familiar with the background of DFT. Could I get the un-scf electron density by ATK?
Take "electron_difference_density" for example, I guess it is come from:
pho1 = pho2(scf) - pho3(a superposition of all isolate atomic charge densities)
so, the pho3 is the un-scf electron density, is there a simple way to get this ?

2.
the specific work in my hand is: I want to get the electron density change because of one vacancy in a bulk system. I already get the electron_difference_density of the my system(with one vacancy), what to do next ?

Thanks~


FangYong

[Anders Blom]

1. Since you can obtain the ElectronDensity rho2 from ATK (DFT), you could compute rho3 as rho2-rho1. But usually you shouldn't need rho3 for anything, unless you have some special plans...

2. You can just subtract the electron densities evaluated for the two systems. Use the ElectronDensity instead of the difference density.