Hello,
I have a few questions and a few suggestions. So far on my first day of using ALPS, I think that it is amazingly powerful and would like to say thank you for all of the work you all have done. I have been studying DMRG by myself making my own codes, but they are fairly simple compared to this. I have figured out the basics of the Heisenberg model with the help of the tutorials and obtained the Haldane gap, but I want to make sure that I am doing the fermionic Hubbard model correctly. Here is the parameter file I am using:
LATTICE="open chain lattice" SWEEPS=4 MAXSTATES=100 { MODEL="fermion Hubbard", L=8, N_total=8, U=10 }
Is this correct for a simple calculation of the ground state?
Also, I was looking through the Models tutorial and noticed under the "Hamiltonian descriptions" subtopic that the SITETERM has a type. Does the type correspond to a given site that it applies to? For instance, could I set the first site to have a repulsion term of U and the second term to have a repulsion term of 2*U and so on? If not, is there a way to do this?
As far as suggestions, I had to figure some things out when installing under Windows/Cygwin and thought that I could offer some modifications to the installation instructions. The biggest obstacle was setting the $PATH to include the binaries folder in the Installation folder. I can give some other suggested changes regarding if they are wanted. I also noticed that the particle in a box demo wasn't working for me. (The error message using parm1 in the tutorials folder is "EXCEPTION: bad lexical cast: source type value could not be interpreted as target" when following the instructions of the tutorial page) Lastly, I was wondering if the links could be made to work for the user workshop page if the files exist. I think they would be a great help.
Thank you for your efforts and for any help you can offer,
Justin Peel