Hi Francesco, Crystal and Gaussian are all-electron codes with Gaussian basis sets while Siesta is a pseudopotential code with numerical atomic orbitals as a basis set so there is no clear one-to-one correspondence between the basis sets you used there and the basis sets used by Siesta. You can read more about basis sets and the inner workings of Siesta in many of these cool tutorials:
http://departments.icmab.es/leem/siesta/Documentation/Tutorials/index.html Regarding Ge. It can be tricky to accurately describe the band structure of Ge within the pseudopotential method. Here is a recent paper that briefly discusses this issue: http://www.sciencedirect.com/science/article/pii/S0927025614007940 As far as I understand, you can get their optimized Ge pseudo from the supplemental material and then you can try to use the default DZP or their optimized basis set from Table 2. Also, there is no such thing as a universal "good" basis set. The default DZP might be fine for many observables but may be insufficient for others. I recommend picking an observable you are interested in and checking the convergence or the sensitivity of the results as you increase the quality of the basis set. Sincerely, Marton Voros -- Materials Science Division Argonne National Laboratory On Fri, Mar 18, 2016 at 6:04 AM, Francesco Macheda <[email protected]> wrote: > Hi all, > I'm new user of SIESTA code. I have simulated Germanium bulk with other > codes (namely QE and CRYSTAL14) and i wanted to compare with SIESTA > results. As I'm a very beginner, I don't exactly know how to translate > CRYSTAL14 (or GAUSSIAN94) basis sets to SIESTA. If someone have hints, > please tell me. Anyway, it would suffice at least to have a Ge basis set, > which I didn't find in SIESTA database. If someone has a good Ge basis set, > I'd really appreciate the sharing. > > Thank for attention, > Francesco Macheda > Graduand at Pisa University >
