September 2011 - Comp-phys-alps-users

ALPS 2.0.1 released
by Matthias Troyer 19 Sep '12

19 Sep '12

Dear ALPS users, ALPS 2.0.1 has been released. This is the version included with the ALPS paper: B. Bauer et al., J. Stat. Mech. (2011) P05001, which is available at : http://www.iop.org/EJ/abstract/1742-5468/2011/05/P05001 .Besides references to this paper, this release contains many minor bug fixes. The MacOS X 10.5 binary release will be uploaded shortly. The others are ready for download. Best regards Matthias Troyer

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ALPS release 2.0.2b1
by Matthias Troyer 07 Oct '11

07 Oct '11

Dear all, We prepared a beta release for ALPS 2.0.2, with a few changes such as - a number of bug fixes - a faster DMRG code - support for MacOS X Lion The beta version is posted on the ALPS web page. We plan to release 2.0.2 once we get some feedback. 2.0.2 will also be the version to be used in an upcoming alpha version of VisTrails 2.0 Matthias

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alps2.0 cpu
by muzi352 27 Sep '11

27 Sep '11

dear editor: alps 2.0 cpu use very largy ,for example : why? thank you

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alps2.0 cpu
by muzi352 26 Sep '11

26 Sep '11

dear editor: alps 2.0 cpu use very largy ,for example : why? thank you

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how to define the vector chirality
by muzi352 19 Sep '11

19 Sep '11

dear editor : how to calculate the vector chirality in the dmrg of ALPS? sometimes only calculate the correlation have not identify the different phase .thanks

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NONLOCAL parameter in Worm algorithm
by Vipin Varma 16 Sep '11

16 Sep '11

Dear ALPS users/developers, I have a quick question about the NONLOCAL parameter used in the worm algorithm. The ALPS-Wiki mentions it to be a compile time option that one must "undefine to speed up the code for local interactions". However when I run a simulation (linear chain of hardcore bosons with finite chemical potential) for a given chain size with and without this parameter un-defined, the results are quite different. Secondly, the results for the runs with NONLOCAL=0 for different chain sizes are quite comparable to each other (though not exactly equal) and to the exact result for a single-site calculation (again though not exactly equal). I am trying to understand what this parameter does and why the results change when it is set versus unset; any ideas will be appreciated. Thanks, Vipin

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How to set some measurements?
by 赵炜 12 Sep '11

12 Sep '11

Hi ALPS developers and users, I am wandering how can I set to measure the magnetization and susceptibility in using DMFT Hubbard Model. Especially how to set the operator. Thanks for any help. Zhao Wei

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Confusion about the size of lattice.
by 赵炜 12 Sep '11

12 Sep '11

Hi ALPS developers and users, Please forgive my ignorance, but I really cannot find answer. One of the key ideas of DMFT is to replace "other sites" by a "bath" or "effective medium". We have to set a size of the lattice to be replaced, right? Maybe 100x100 or 200x200. But I can not find the lattice size set in the parameter file. Zhao Wei

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Self Energy in DMFT Code
by Hunter Sims 11 Sep '11

11 Sep '11

Dear All, I have written a little DMFT code using the ALPS CTQMC impurity solver. The code accepts an arbitrary Hamiltonian (eventually with the goal of doing some form of LDA+DMFT, currently just a model tight-binding Hamiltonian). Firstly, I was wondering what might be done to address the large amount of noise in the tail of the self energy (after the first 20 or so Matsubara frequencies, the noise is a couple of orders of magnitude larger than the "signal"). I suppose it is not surprising that subtracting the inverses of two small numbers would lead to this sort of thing. Secondly, the type of lattice (a Bethe lattice by default in the ALPS dmft code) seems to enter into the picture via a set of three constants in the Fourier transforms. For the forward transform, these seem to be boundary terms in a numerical integration-by-parts method. They also appear in the backward transform, although it is less clear to me what their function might be. I was also wondering, if it does not exceed the scope of a mailing list query, if there are other places in the provided dmft code in which the Bethe lattice is tacitly assumed. Any help would be greatly appreciated. Regards, Hunter -- Hunter Sims Center for Materials for Information Technology University of Alabama Box 870209 Tuscaloosa AL 35487-0209 205-310-9369

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A lot of＂-nan" and "inf" in output file
by 赵炜 02 Sep '11

02 Sep '11

Dear Matthias, When I ran dmft-02-hybridization in tutorial in python, I found that in G_tau and selfenergy file there is lots of "-nan" and "inf". Is it because of my computer or because I did not install alps right? How can I solve the problem? Sincerely, Zhao Wei(A student from China)

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