QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: 395235863 on March 17, 2016, 15:12

Title: Why different boundary conditions get different fermi level?
Post by: 395235863 on March 17, 2016, 15:12

Why different boundary conditions get different fermi level?
examples are given as pic.1

Title: Re: Why different boundary conditions get different fermi level?
Post by: Jess Wellendorff on March 18, 2016, 10:05

Changing a boundary condition may shift the electronic eigenvalue spectrum, and therefore also the Fermi level. Look slike you also used different k-point samplings. This will definitely result in a shift of the Fermi level, but may not affect band energy differences much.

Title: Re: Why different boundary conditions get different fermi level?
Post by: Anders Blom on April 7, 2016, 11:19

And, most importantly, the absolute value of the Fermi level doesn't mean anything, since you don't know the energy zero-point reference. All band structures are always reported relative the Fermi level  and that's typically all that matters.