Dear BR/Yujia, The values of IP and EA, and of the work function as a consequence, is sensitive to the confinement imposed on basis orbitals. Using the default value of energy shift (0.01 Ry) I also obtained a value of fermi level for Au(111), -4.1eV, which greatly differs from those previously reported. I have obtained a better result, -5.1eV, decreasing the value of energy shift to 0.001 Ry. As it is possible to see in Nanotechnology *21* (2010) 065705, the value of Au(111) fermi level converges to that obtained using plane waves (-5.25eV) in the limite of very small basis set confinement.
Best, Ronaldo On Fri, Dec 24, 2010 at 5:33 AM, zjuyangyj <[email protected]> wrote: > Dear all, > Recently I am calculating the work functions or fermi levels of different > metals. However, my results seem to be incorrect. For example, I got the > fermi level for Au as -3.68eV, which greatly differs from previous > theoretically or experimentally reported values, which range from -4.8eV to > -5.3eV. Also I got the fermi level for Pt as -3.99eV, also largely differing > from correct values. > > I want to know what might be the possible reasons for incorrect fermi > levels, and when calculating fermi levels, what are the > important/relevant parameters? I am calculating very thin metal films (tens > of atom layers), and I found the number of layers an important parameter. > Also I want to know whether the fermi levels of bulk and thin film metal > differs a lot. > > Thank you for your attention. > > BR/Yujia >
