Hello,

I know that when dealing with metallic systems, so called smearing is very importend.

ATK uses Fermi-Dirac smearing. Thus an electron temperature is introduced, which softenes the step in the occupation of states at the Fermi level.

The advantage of this method (as I understand) is the fact, that the electron temperature in Fermi-Dirac smearing can be interpreted as the real physical temperature of the system.

However, by looking on other codes and some publications I noticed that there exist other smearing methods. The most prominent are:

- (No smearing (not recommended for metals!))

- Fermi-Dirac

- Gaussian

- Methfessel-Paxton

- Marzari-Vanderbilt

- Tetrahedron method (with Blügel correction)

Different codes (I looked at siesta, quantum espresso and castep) use different smearing methods as their default. A new siesta-manual praises the Methfessel-Paxton method (can use high electron temp. and low numer of k-points).

Anyway, if you have the time ;-) or don't know what to put in a future release you could consider implementing one or the other of the above methods.