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Can the mps_optim calculate the entanglement spectrum of the lattice with two cuts ?
by X****** **** 19 Aug '17

19 Aug '17

Dear all, Can the mps_optim calculate the entanglement spectrum of the lattice with two cut ? For instance, the lattice is separated to A B C, how to calculate the -Ln(\rho_B), \rho_B=Tr_{A,C} |\Phi><\Phi|. Thanks, Xiaofan Zhou

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Problem on finding xsl path
by Jin Hyoun Kang 19 Aug '17

19 Aug '17

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Re: [ALPS-users] [ALPS} Using nvblas to boost calculations
by John Ian Kenneth E. Felismino 18 Aug '17

18 Aug '17

We wanted to use nvblas to intercept any level 3 blas operations. My colleagues and I are mainly using mps-optim for dmrg applications. Thanks, Ian Felismino On Aug 18, 2017 12:02 AM, "Matthias Troyer" <troyer(a)phys.ethz.ch> wrote: Which calculations do you want to boost that way? > On 17 Aug 2017, at 01:03, John Ian Kenneth E. Felismino < jfelismino(a)nip.upd.edu.ph> wrote: > > Greetings! > > I was wondering if it is possible to add nvblas from cuda 8.0 when building alps to boost the speed of the calculations. This possible increase in speed and efficiency will help a lot to me and my colleagues who have share computing resources in the laboratory. > > Thanks, > Ian Felismino > > > ---- > Comp-phys-alps-users Mailing List for the ALPS Project > http://alps.comp-phys.org/ > > List info: https://lists.phys.ethz.ch//listinfo/comp-phys-alps-users > Archive: https://lists.phys.ethz.ch//pipermail/comp-phys-alps-users > > Unsubscribe by writing a mail to comp-phys-alps-users-leave@ lists.phys.ethz.ch. ---- Comp-phys-alps-users Mailing List for the ALPS Project http://alps.comp-phys.org/ List info: https://lists.phys.ethz.ch//listinfo/comp-phys-alps-users Archive: https://lists.phys.ethz.ch//pipermail/comp-phys-alps-users Unsubscribe by writing a mail to comp-phys-alps-users-leave@ lists.phys.ethz.ch.

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mps_optim can not calculate 1D Kitaev chain
by Xiaofan Zhou 09 Aug '17

09 Aug '17

Dear all, I write some files to calculate 1D Kitaev chain. However, it dose not work. All files are attached. The HAMILTONIAN contain the code: -t#*(cdag(i)*c(j)+cdag(j)*c(i)-c(i)*c(j)-cdag(j)*cdag(i)) . Best, Xiaofan Zhou 2017-08-08

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Nonperiodic deterministic lattice
by Andre Vieira 04 Aug '17

04 Aug '17

Hi, is there a way of using the 'inhomogeneous chain lattice' definition to implement an arbitrary nonperiodic but deterministic lattice for QMC applications? To be specific, I would like to implement a spin model in which, for instance, J(1), J(2), J(3), etc. are all different, but not defined by a simple function, nor randomly chosen. Thanks in advance for your help, Andre.

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Two-dimensional system with MPS
by H 13 Jul '17

13 Jul '17

Dear Michele or others, In your paper (arXiv:1407.0872)'s abstract you mentioned the MPS code can handle 2D system. Is it as simple as setting the 'LATTICE' parameter to "open square lattice", or do I need to build a custom 1D lattice with long-range coupling? I tried setting 'LATTICE' to "open square lattice" but the results seems different from my ED result. The system is spinful fermionic. Could it be due to fermion signs not properly taken care of internally? Ultimately I need to simulate a small 3D system (3x3x3). Can I use the internal cubic lattice or do I need to build a custom 1D lattice with long-range coupling?

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parallel data computing in the alps code
by hamid mosadegh 13 Jul '17

13 Jul '17

Dear all For the MPS computing with a large bond dimension, I need to use parallel computing. But when I use the following commends, instead of a parallel data run, calculations are repeated several times. can alps do these calculations? Thanks for you attentions #setup environment export TOPDIR=$HOME/work/FINAL/ export MPIPATH=/share/binary/mpich2-1.4.1p1/bin/ export TMP=/home/scratch/ # generate nodelist cd $TOPDIR # setup run NP=8 #NAMDCONF=apoa1.namd # run $MPIPATH/mpirun -np $NP mps_optim --mpi --write-xml K.in.xml -- H. Mosadeq Shahr-e-Kord University (SKU), Shahr-e-Kord , Iran

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Problem with DMRG and an Ising model
by Alexander Henry 12 Jul '17

12 Jul '17

Dear ALPS, I'm having some troubling getting a sensible result using DMRG with ALPS 2.3.0 on a simple transverse Ising model (i.e. using the "spin" model with Jz != 0, Gamma != 0). Other methods seem to get the correct result with the same parameters. It seems to be the Gamma term which causes the trouble. I've pasted a script below which demonstrates the problem. The script gives me the following output, with the second number being the ground state energy found by each method: Model fulldiag: {10.0: -5.3178022046739857} Model sparsediag: {10.0: -5.3178022046739937} Model mps_optim: {10.0: -5.3178022046739919} Model dmrg: {10.0: -213.49032836522568} Adjusting the various DMRG parameters produces similar results of E0 ~= -210. I assume I am doing something wrong, or perhaps the Gamma term isn't supported by DMRG? I have searched the mailing list archive without success. Ultimately, I want to use DMRG on a more complex model which includes a term similar to the Gamma / Sx term in the spin model. Thank you for your great work, Alex Henry The script: ########################## import pyalps import numpy as np import matplotlib.pyplot as plt import copy import math models = ['fulldiag', 'sparsediag', 'mps_optim', 'dmrg'] parms = [{ 'LATTICE' : "chain lattice", 'MODEL' : "spin", 'local_S' : 0.5, 'Jxy' : 0, 'Jz' : 1, 'Gamma' : 1, 'h' : 0, 'NUMBER_EIGENVALUES' : 1, 'L' : 10, }] def process(prefix, prog): input_file = pyalps.writeInputFiles(prefix, parms) res = pyalps.runApplication(prog, input_file) data = pyalps.loadEigenstateMeasurements(pyalps.getResultFiles(prefix=prefix)) return data def get_results(d): E0 = {} for Lsets in d: L = pyalps.flatten(Lsets)[0].props['L'] allE = [] for q in pyalps.flatten(Lsets): allE += list(q.y) allE = np.sort(allE) E0[L] = allE[0] return E0 results = {} for model in models: name = "ising_" + model data = process(name, model) results[model] = (get_results(data)) for model in models: print "Model " + model + ": " + str(results[model]) #############################

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Long Range Kitaev Model site dependent Hamiltonian
by John Ian Kenneth E. Felismino 05 Jul '17

05 Jul '17

Hi! The hamiltonian I'm using is attached as a picture file. As you can see, the bond terms are proportional to abs(i - j)^\alpha. i was wondering if this is possible in Alps because I have tried doing it (crudely) with DMRG and found that it did not produce an output xml. I had simply added the term "/abs(i-j)^alpha#" in my hamiltonian. When I remove this term, the Hamiltonian works, so clearly the problem is with this proportionality term. Thanks. Ian Felismino

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Multithreading in MacOSX
by H 03 Jul '17

03 Jul '17

Hello, I have installed alps via conda on a Linux OS (on a cluster) and on a Mac OS (on my desktop). I noticed that with the same code (using the MPS routines), on LinuxOS all the cores are utilized but on the MacOS only one core is used. Is there a method to make multithreading works on MacOS?

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