June 2010 - Comp-phys-alps-users

Problems with worms??
by Jakub Zakrzewski 27 Oct '10

27 Oct '10

Hello, Sometimes QMC worm code (used on Bose-Hubbard) terminates with the following error: here come first earlier succesful simulations then ... Created run 85 remote on Host ID: 84 Created run 86 remote on Host ID: 85 Created run 87 remote on Host ID: 86 Created run 88 remote on Host ID: 87 All processes have been assigned Checking if Simulation 1 is finished: not yet, next check in 120 seconds ( 0% done). q = -0 state1 = 0 state2 = 0 bond_type = 0 zero matrix element in remove_jump application called MPI_Abort(MPI_COMM_WORLD, -2) - process 67 Could somebody advice what I can do? Best regards Kuba

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[help] cannot compute local magnetization in ED
by jun wen 10 Aug '10

10 Aug '10

Hello All, I was trying to compute the local <S> in the Kitaev model defined on the honeycomb lattice with Exact Diagnolization Here is my parameter file: MODEL="kitaev"; LATTICE="honeycomb lattice"; LATTICE_LIBRARY="../../../definitions/kitaev/lattices.xml"; MODEL_LIBRARY="../../../definitions/kitaev/models.xml"; MEASURE_LOCAL[Local Sz]=Sz; MEASURE_LOCAL[Local Sx]=Sx; MEASURE_LOCAL[Local Sy]=Sy; local_S=1/2; L=2; W=2; J=1; However, in the output xml file, there are no such terms as the Local Sz or Local Splux or Local Sminus. I wonder if anyone could kindly point out what is the problem. The Kitaev model is defined in the following models.xml Thanks a lot! <MODELS> <SITEBASIS name="spin"> <PARAMETER name="local_spin" default="local_S"/> <PARAMETER name="local_S" default="1/2"/> <QUANTUMNUMBER name="S" min="local_spin" max="local_spin"/> <QUANTUMNUMBER name="Sz" min="-S" max="S"/> <OPERATOR name="Splus" matrixelement="sqrt(S*(S+1)-Sz*(Sz+1))"> <CHANGE quantumnumber="Sz" change="1"/> </OPERATOR> <OPERATOR name="Sminus" matrixelement="sqrt(S*(S+1)-Sz*(Sz-1))"> <CHANGE quantumnumber="Sz" change="-1"/> </OPERATOR> <OPERATOR name="Sz" matrixelement="Sz"/> </SITEBASIS> <SITEOPERATOR name="Sx" site="x"> 1/2*(Splus(x)+Sminus(x)) </SITEOPERATOR> <SITEOPERATOR name="Sy" site="x"> 1/2/I*(Splus(x)-Sminus(x)) </SITEOPERATOR> <BASIS name="spin"> <SITEBASIS ref="spin"/> </BASIS> <HAMILTONIAN name="kitaev"> <PARAMETER name="J1" default="1"/> <PARAMETER name="Jz" default="J1"/> <PARAMETER name="Jx" default="J1"/> <PARAMETER name="Jy" default="J1"/> <BASIS ref="spin"/> <BONDTERM type="0" source="i" target="j"> Jz*Sz(i)*Sz(j) </BONDTERM> <BONDTERM type="1" source="i" target="j"> Jx*Sx(i)*Sx(j) </BONDTERM> <BONDTERM type="2" source="i" target="j"> Jy*Sy(i)*Sy(j) </BONDTERM> </HAMILTONIAN> </MODELS> Jun

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Complex numbers
by Sebastian Greschner 23 Jul '10

23 Jul '10

Hi, when I try to define a complex Hamiltonian (e.g. some extended Heisenberg-model with Sx _and_ Sy=-I/2(Splus-Sminus) couplings to external fields) fulldiag or other ALPS-programs end with the error "can not convert complex number into real one" Is this a general restriction for ALPS, or did I miss some configuration or compile option? If not - do you know any patch or work-around to enable complex-numbers? Thanks in advance and greetings, Sebastian

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[help] How to compute the expectation value of 4 operators( two creation and two destruction operators)
by Jun Wen 26 Jun '10

26 Jun '10

Hello all, I have been trying to compute the expectation value of cdag(1) c(2) cdag(3) c(4) where two creation and two destruction operators are involved and 1, 2 ,3 and 4 label the sites in a spinless Hubbard model. Could anyone kindly tell me how I should define this in the parameter file or in the models.xml? Thanks a lot! Best, Jun

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Could you please remove me from this group?
by Huisky 24 Jun '10

24 Jun '10

Hi all, I don't know why I'm involved here, could you please do me the favor? Regards Hui

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installation problem hdf5 alps 2.0.0b1
by Sebastian Huber 23 Jun '10

23 Jun '10

Hi everybody, I struggle with the installation of alps2 on our linux cluster. The problem boils down to the following error message after successful compilation: ../ALPS/bin/sparsediag: error while loading shared libraries: libhdf5.so.6: cannot open shared object file: No such file or directory which I am not sure how to relate to the following answer I get from the configuration with cmake: -- Found HDF5: /srv01/condgrp/huber/opt/lib/libhdf5.so.6 The parameters I give cmake are: ../cmake-2.8.1/bin/cmake -D BLAS_LIBRARY=/usr/lib64/libblas.so.3.0.3 -D LAPACK_LIBRARY=/usr/lib64/liblapack.so.3.0.3 -D CMAKE_INSTALL_PREFIX=$HOME/ALPS -D LAPACK_64_BIT=ON -D HDF5_INCLUDE_DIR=/srv01/condgrp/huber/opt/include/ -D HDF5_LIBRARIES=/srv01/condgrp/huber/opt/lib/libhdf5.so.6 ~/alps-2.0.0b1-r4556-src-with-boost/alps/ Any suggestion is highly appreciated! Sebi -- Sebastian Huber Department of Condensed Matter Physics The Weizmann Institute of Science 76100 Rehovot Web: http://www.weizmann.ac.il/~huber Tel: +972 8 934 4258

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Calculating the spinon gap for finite system
by Vipin Varma 22 Jun '10

22 Jun '10

Hi I'm trying to get the gap (between the Sz=0 sector and the Sz=1/2 i.e. spinon) for a spin-1/2 anti-ferromagnetic Hiesenberg chain for a finite system L=4. No eigenvalues are calculated in the output file when I perform sparse diagonalization on the below parameter file for getting the spinon eigenvalue: MODEL="spin"; LATTICE="chain lattice"; LATTICE_LIBRARY="../lattices.xml" MODEL_LIBRARY="../models.xml" CONSERVED_QUANTUMNUMBERS="Sz"; local_S=1/2; J=1; {L=4; Sz_total=1/2;} It seems only the sectors with Sz= {-1,0,+1} can be input to the Lanczos algorithm. Can somebody tell me what I am missing? Thanks, Vipin

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First ALPS 2.0 beta release
by Matthias Troyer 04 Jun '10

04 Jun '10

Dear ALPS developers and users, We have posted ALPS 2.0b1 on the web page. This is the first beta release of ALPS 2. It's main purpose is to provide a stable version to test on various platforms, and to provide feedback about installation and compilation issues. The libraries and applications should be at least as stable as version 1.3.4 was. Any potential issues should be due to dependencies on new libraries, a new build system, and support for more operating systems. Download and installation instructions are posted at http://alps.comp-phys.org/mediawiki/index.php/Download_and_install_ALPS_2 Major new features are - Use of HDF5 as binary file format for results, replacing XML for large data sets, as requested by power users. Specifying the option --write-xml with the applications will still write the old XML files in addition - Use of CMake as a new build system - Support for Windows, as requested by many users - Ready-made binary installers for MacOS X and Windows, as desired by many users. - More powerful Python based evaluation tools replacing the old XSLT based ones - Integration with the VisTrails workflow and provenance tool - A new DMFT application - Updated applications with new features - A new and more extensive set of tutorials (in progress). This first beta release will also be used to finish development on the tutorials. Progress on tutorials and documentation will be seen on the Wiki over the coming six weeks. Another beta release 2.0b2 is planned for early July, containing new features, improved documentation and tutorials and numerous improvements (and probably also bug fixes). I would like to encourage all to download and install this beta release and report problems or provide feedback on the mailing list. We want to solve all installation issued before 2.0b2 comes out. Besides all the ALPS developers I want to especially thank the following people who contributed major time to the development of new features in ALPS 2: Bela Bauer Sebastian Fuchs Lukas Gamper Jan Gukelberger Emanuel Gull Ryo Igarashi Tama Ma Olivier Parcollet Brigitte Surer Synge Todo as well as from the VisTrails team: Juliana Freire David Koop Emanuele Santos Claudio Silva For the ALPS team, Matthias Troyer

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question on the local measurement and definition
by jun wen 03 Jun '10

03 Jun '10

Dear all, I would like to ask you a question about the local measurement and definition: I want to calculate the density of fermions and the bond order cdag(i)*c(j) on each site and each bond in a spinless Hubbard model. How should I do it? Thank you very much! Best Jun Here are my files: ============================================================= lattice.xml <LATTICES> <LATTICE name="triangular lattice" dimension="2"> <PARAMETER name="a" default="1"/> <BASIS><VECTOR>a 0</VECTOR><VECTOR>a/2 a*sqrt(3)/2</VECTOR></BASIS> <RECIPROCALBASIS><VECTOR>2*pi/a -2*pi/a/sqrt(3)</VECTOR><VECTOR>0 4*pi/a/sqrt(3)</VECTOR></RECIPROCALBASIS> </LATTICE> <UNITCELL name="Kagome" dimension="2"> <VERTEX><COORDINATE>0 0</COORDINATE></VERTEX> <VERTEX><COORDINATE>0.5 0</COORDINATE></VERTEX> <VERTEX><COORDINATE>0 0.5</COORDINATE></VERTEX> <EDGE><SOURCE vertex="1"/><TARGET vertex="2"/></EDGE> <EDGE><SOURCE vertex="1"/><TARGET vertex="3"/></EDGE> <EDGE><SOURCE vertex="2"/><TARGET vertex="3"/></EDGE> <EDGE><SOURCE vertex="1"/><TARGET vertex="2" offset="-1 0"/></EDGE> <EDGE><SOURCE vertex="2"/><TARGET vertex="3" offset="1 -1"/></EDGE> <EDGE><SOURCE vertex="1"/><TARGET vertex="3" offset="0 -1"/></EDGE> </UNITCELL> <LATTICEGRAPH name = "Kagome lattice"> <FINITELATTICE> <LATTICE ref="triangular lattice"/> <PARAMETER name="W" default="L"/> <EXTENT dimension="1" size="L"/> <EXTENT dimension="2" size="W"/> <BOUNDARY type="periodic"/> </FINITELATTICE> <UNITCELL ref="Kagome"/> </LATTICEGRAPH> </LATTICES> ========================================= models.xml <MODELS> <SITEBASIS name="spinless fermion"> <QUANTUMNUMBER name="N" min="0" max="1" type="fermionic"/> <OPERATOR name="cdag" matrixelement="1"> <CHANGE quantumnumber="N" change="1"/> </OPERATOR> <OPERATOR name="c" matrixelement="1"> <CHANGE quantumnumber="N" change="-1"/> </OPERATOR> <OPERATOR name="n" matrixelement="N"/> </SITEBASIS> <SITEOPERATOR name="density" site="x"> cdag(x)*c(x) </SITEOPERATOR> <BASIS name="spinless fermion"> <SITEBASIS ref="spinless fermion"/> <CONSTRAINT quantumnumber="N" value="N_total"/> </BASIS> <BONDOPERATOR name="fermion_hop" source="x" target="y"> cdag(x)*c(y)+cdag(y)*c(x) </BONDOPERATOR> <HAMILTONIAN name="spinless fermions"> <PARAMETER name="mu" default="0"/> <PARAMETER name="t" default="1"/> <PARAMETER name="V" default="0"/> <PARAMETER name="t'" default="0"/> <PARAMETER name="V'" default="0"/> <PARAMETER name="t0" default="t"/> <PARAMETER name="t1" default="t'"/> <PARAMETER name="V0" default="V"/> <PARAMETER name="V1" default="V'"/> <BASIS ref="spinless fermion"/> <SITETERM site="i"> <PARAMETER name="mu#" default="mu"/> -mu#*n(i) </SITETERM> <BONDTERM source="i" target="j"> <PARAMETER name="t#" default="0"/> <PARAMETER name="V#" default="0"/> -t#*(cdag(i)*c(j)+cdag(j)*c(i)) + V#*n(i)*n(j) </BONDTERM> </HAMILTONIAN> </MODELS> ============================================= parameters.txt MODEL="spinless fermions"; LATTICE="Kagome lattice"; LATTICE_LIBRARY="definitions/lattices.xml" MODEL_LIBRARY="definitions/Copy of models.xml" t=1; N_total=4; W=2; L=2; CONSERVED_QUANTUMNUMBERS="N"; NUMBER_EIGENVALUES=3; MEASURE_AVERAGE[kinetic-energy]=fermion_kinetic_energy; MEASURE_AVERAGE[density]=density; {V=30;}

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questions on exact diagonalization in ALPS
by jun wen 01 Jun '10

01 Jun '10

Dear all, I wonder if I can ask you how to setup a script to run an exact diagonalization of a spinless extended Hubbard model on a 4-sites system. I have read the tutorial but still do not get the idea of how to do it. I want to specify the model Hamiltonian with a nearest neighbor hopping t, a nearest neighbor interaction strength V1 and a second nearest neighbor interaction strength V2. Where should I define these parameters? thanks a lot for your kind help! Best regards, Jun

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