July 2015 - Comp-phys-alps-users

Error when using 'singlesite' optimization and 'storagedir' together for MPS based DMRG
by Wei.Su 22 Jul '15

22 Jul '15

I occured an error "Intel MKL ERROR: Parameter 10 was incorrect on entry to DGEMM " when using 'singlesite' optimization and 'storagedir' together. I'm not sure if this is an error of MKL or one of the MPS code in ALPS However it runs ok if i turn off the "storagedir" option or use the "twosite" optimization schedule. Here comes the python script #--------------------------------------------------------------------------------------------# import pyalps import numpy as np import matplotlib.pyplot as plt import pyalps.plot #prepare the input parameters parms = [ { 'optimization' : 'singlesite', 'LATTICE' : 'open chain lattice', 'L' : 20, 'MODEL' : 'spin', 'local_S0' : '0.5', 'local_S1' : '1', 'CONSERVED_QUANTUMNUMBERS' : 'N,Sz', 'Sz_total' : 0, 'J' : 1, 'SWEEPS' : 4, 'NUMBER_EIGENVALUES' : 1, 'MAXSTATES' : 50, 'storagedir' : 'storage' } ] #write the input file and run the simulation input_file = pyalps.writeInputFiles('parm_spin_one',parms) res = pyalps.runApplication('mps_optim',input_file,writexml=True) #----------------------------------------------------------------------------------------# -------Su Wei-------

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Inconsistent comment in generate_spline_matrix in the DMFT folder
by Kuangshing Chen 22 Jul '15

22 Jul '15

Hi, The function generate_spline_matrix in fouriertransform.C in the dmft folder shows the comments as follows: // A is the matrix whose inverse defines spline_matrix // // 6 6 // 1 4 1 // 1 4 1 // A = ... // // 1 4 1 // -2 0 0 2 However, the following codes, dense_matrix A = 4*dt/6.*boost::numeric::ublas::identity_matrix<double>(Np1); for (int i=1; i<Np1-1; i++) { A(i,i-1) = dt/6.; A(i,i+1) = dt/6.; } A(0,0) = 1.; A(0, Np1-1) = 1.; A(Np1-1, 0) = -2.*dt/6.; A(Np1-1, 1) = -1.*dt/6.; A(Np1-1, Np1-2) = 1*dt/6.; A(Np1-1, Np1-1) = 2*dt/6.; the red lines will make the matrix looks like // 6 6 // 1 4 1 // 1 4 1 // A = ... // // 1 4 1 // -2 *-1* *1* 2 Is the comment correct or the code correct? Any reference for this algorithm? Thank you, Kuang-Shing Chen

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Acquiring data to susceptibility for Ising`s Model
by Felipe da Cruz Rodrigues 17 Jul '15

17 Jul '15

Hello all. Someone know how can I to acquire the data for susceptibility in Ising's Model (ex: tutorial 7)? p.s.: I don't want the generated graphic for the susceptibility in vistrails, but only the data. Thanks a lot! -- Felipe da Cruz Rodrigues Mestrando em Física pela Universidade Federal de Lavras Graduado em Física (Licenciatura) - UFLA

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mps_optim example 1: itinerant fermions in the Hubbard ladder
by Dominique Delande 09 Jul '15

09 Jul '15

Dear all, I am trying to use mps_optim and have serious problems. I try to run Example 1 (itinerant fermions in the Hubbard ladder) presented in M. Dolfi et al, CPC 185, 3430 (2014). I downloaded the mmcs1.zip file which should contain all scripts and results. When I run the python script for Example 1, my results are quite different from what they should be: * No "EnergyVariance" variable in the result files sim.taskX.out.h5 * All "pair field" results are zero, or vanishingly small (of the order of 1.e-300). * In the result files extracted from mmcs1.zip (e.g. sim.task1.out.h5), there are additional results such as "Energy^2", "Local density down", "dens corr down-down", etc. * In the result files extracted from mmcs1.zip (e.g. sim.task1.out.h5), in the "parameters" section, there are things like MEASURE_HALF_NN_CORRELATIONS which are not defined in the simulation parameters (most probably it it the same as MEASURE_HALF_CORRELATIONS). I thus have the impression that the results files provided in mmcs1.zip have NOT been obtained using the provided python scripts. More importantly, how to obtain correct "EnergyVariance" and "pair field" results ? I am using alps-2.2.b3-r7462, compiled from source on a Fedora 21 x86_64 machine, using the GNU compilers and Intel MKL libraries. Thanks in advance for your help. Dominique -- Dominique Delande (Dominique.Delande(a)lkb.upmc.fr) Laboratoire Kastler-Brossel - Case 74 - Universite P. et M. Curie 4, place Jussieu, F-75252 Paris Cedex 05, FRANCE Phone : +33 1 44 27 27 97 - Fax : +33 1 44 27 38 45 Acces : Tour 13, Couloir 12-13, 3eme etage - Bureau 316

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Error when searching for excited states with MPS code
by Wei.Su 08 Jul '15

08 Jul '15

I was using MPS code in ALPS to calculate exited states of the fermion Hubbard model when there throwed an error -------------------------------------------------------------------------------------------- Sweep 0, optimizing sites 19 and 20 Input <MPS|O[0]> : 0 Output <MPS|O[0]> : -nan JCD used 8 iterations. Time elapsed in JCD: 0.19799719 MPS overlap: 0 Energy 1 2.341151156e-310 Exception thrown: Error in SVD! -------------------------------------------------------------------------------------------------- This error vanished when the "total number" was less than 10 or great than 20 (or around) or the 'MAXSTATES' is greater than about 80. In the attachment I deliver my python script. -------------------------------------------------------------------------------------------------------------- import pyalps import numpy as np parms=[] for L in [40]: for P in [12]: # for P in [55,56,57,58,59,60,61,62]: parms.append({ 'LATTICE' : "open chain lattice", 'L' : L, 'MODEL' : "fermion Hubbard", 'CONSERVED_QUANTUMNUMBERS' : 'Nup,Ndown', 'Nup_total' : P, 'Ndown_total' : P, 'mu' : 0.0, 't' : 1.0, 'U' : 0.0, 'SWEEPS' : 4, 'MAXSTATES' : 50, 'NUMBER_EIGENVALUES' : 2, 'storagedir' : 'storage', }) #write the input file and run the simulation input_file = pyalps.writeInputFiles('parm_tsc',parms) res = pyalps.runApplication('mps_optim',input_file,writexml=True) -------------------------------------------------------------------------------------------------------------------- -- -------苏威-------

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1D-Spin 1/2 -Chain with 3-site terms
by T. Bilitewski 02 Jul '15

02 Jul '15

Hi, I am trying to simulate a 1D-chain Spin 1/2 chain with a Hamiltonian containing 3-site terms, e.g. of the type S(i) S(i+1) S(i+2). From my understanding the only way to implement this currently is to extend the basis per site to consist of 2 spins, spin1 and spin2, which allows me to write the 3-site term as a usual bond term. I have implemented this in the attached file model_extended_basis.xml Doing this then requires rewriting the 2-site terms, specifically the term S_plus(i) *S_minus(i+1)+h.c. will become a site term for even i S1_plus(i) *S2_minus(i) +h.c. and a bond term for uneven i S2_plus(i)*S1_minus(i+1) +h.c. This implementation works flawlessly when using the full_diag routine. However, when using the dmrg routine, weird behaviour occurs. Firstly, restricting the simulation to total S_z sectors works within the full_diag, but fails in dmrg for S_z !=0 . Secondly, the bond term seems to be treated fine, i.e. only including the bond term in the Hamiltonian, the results agree with the full_diag results. However, when including the site-term, the ground-state energy suddenly becomes 100 times the coupling constant, and does not agree with the expectation value of the bond-term anymore, i.e. setting all other terms in the Hamiltonian to 0 and measuring the expectation value of the bond-operator does not agree with E0. I have attached the python scripts to start the simulation as dmrg_simulation_test.py and fulldiag_simulation_test.py I would be very grateful if someone were able to help me. Kind Regards

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Re: [ALPS-users] ALPS - MPS Windows 7 64 bit
by Michele Dolfi 02 Jul '15

02 Jul '15

Dear Benjamin, I’m not really a Windows user, let’s see if anyway I can help you. I just tried installing the latest binary package (which is not very recent) of ALPS and Vistrails in 64bit version. All seems to work for me. In the specific I installed the packages: 1. alps-2.2.b3-win64.exe 2. vistrails-x64-setup-2.1.5-4fe986148829.zip 3. alps-vistrails-2.2.b3-win64.exe Note that the sequence is important, i.e. alps-vistrails has to be installed after vistrails, such that it can install the ALPS module. For further help I should ask you to write to the ALPS mailing list, you might find some Windows users that can help you directly. https://lists.phys.ethz.ch/listinfo/comp-phys-alps-users <https://lists.phys.ethz.ch/listinfo/comp-phys-alps-users> Best, Michele -- ETH Zurich Michele Dolfi Institute for Theoretical Physics HIT G 32.4 Wolfgang-Pauli-Str. 27 8093 Zurich Switzerland dolfim(a)phys.ethz.ch www.itp.phys.ethz.ch +41 44 633 78 56 phone +41 44 633 11 15 fax > On Jun 29, 2015, at 12:02 PM, Benjamin Mille <mille.benjamin(a)gmail.com> wrote: > > Dear Michele, > I am trying to use the MPS-Algorithm you implemented in ALPS. > Using the 32bit Version of Vistrails(V2.1.2) with the 64bit newest > binary of ALPS(2.2.b3-win64) I can use the mps_optim algorithm. When I > try it with the 64bit version of Vistrails(V2.1.2-win64) the program > stops after writing the parameter xml files. I just tried it on the > first mps tutorial with the spin_one_half.py. > Is there a way to get this working? Because I need the 64bit version for > the systems I want to investigate. > > Kind regards > Benjamin Mille >

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