February 2013 - Comp-phys-alps-users

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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Compiling ALPS statically and parallel diagonalization
by Alex Petrescu 28 Feb '13

28 Feb '13

Hello All, I have the following questions related to running ALPS on a cluster. 1) *Compiling static executables.* Is it possible to compile the ALPS executables statically, such that they can be run on a cluster without the need to compile all of ALPS? If not, any hint as to which shared libraries should be copied along with the executable? 2) *MPI error.* Is there any way to run fulldiag or sparse diag with mpi? mpirun -np 2 fulldiag *.xml halts with the following error message: It seems that [at least] one of the processes that was started with mpirun did not invoke MPI_INIT before quitting (it is possible that more than one process did not invoke MPI_INIT -- mpirun was only notified of the first one, which was on node n0). mpirun can *only* be used with MPI programs (i.e., programs that invoke MPI_INIT and MPI_FINALIZE). You can use the "lamexec" program to run non-MPI programs over the lambooted nodes. Thanks for your help, Alex

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How to output eigenvectors from fulldiag/sparsediag?-Solved
by Alex Petrescu 26 Feb '13

26 Feb '13

A look at the source (DiagTask class) shows that adding PRINT_EIGENVECTORS = true to the parameter file prints the basis and the vector for each energy. Sorry for the spam.

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How to output eigenvectors from fulldiag/sparsediag?
by Alex Petrescu 25 Feb '13

25 Feb '13

Hello ALPS, What option should a command line parameter file contain such that fulldiag or sparsediag outputs eigenvectors (besides eigenenergies) in the *.task*.out.xml file? (parameter file attached for spin 1 chain. The output .xml file solely contains energy levels versus good quantum numbers.) Thank you in advance for your answers, Alex LATTICE="chain lattice" MODEL="spin" local_S=1 J=1 CONSERVED_QUANTUMNUMBERS="Sz" MEASURE_ENERGY=true {L=2}

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Spinful bosons
by "Michał Maik" 25 Feb '13

25 Feb '13

Hi All, I am interested in doing some calulations with bosons that have spin. I looked through the model definitions in the ALPS libraries and found the "spinful bosons" site basis. However there seems to be no basis or Hamiltonian that uses this site basis. I was wondering if there is a reason for this or if it is just a matter of creating a basis and Hamiltionian which referances "spinful boson" instead of "boson". Also if that is the case, which QMC code will best work for this model? Thanks. Cheers Michal Maik

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building alps in Ubuntu 12.04
by Emanuele Levi 21 Feb '13

21 Feb '13

Dear all, I have just installed Ubuntu 12.04 on a desktop machine and I want to install ALPS. I downloaded all the required packages successfully, and also the source alps-2.1.1-r6176-src-with-boost.tar.gz<http://alps.comp-phys.org/static/software/releases/alps-2.1.1-r6176-src-wit…> Then I follow exactly the installation tutorial, that works smooth, and I end up with a folder called /opt/alps. The problem is that now I cannot execute any tutorial. In the shell I have no alpspython command available, and if I try to import pyalps in python it tells me that it doesn't exist. Did anyone install it in my way and know if there are additional steps to do? Many thanks for your kind help. Regards. -- Emanuele Levi emanuele.levi(a)gmail.com

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two-leg ladders with unequal on-site couplings
by Giuliano Orso 21 Feb '13

21 Feb '13

Dear ALPS users, I am trying to simulate two-leg ladders models of say hardcore bosons. I need that the lower and upper leg have different chemical potentials, mu0 and mu1 respectively. How can I implement that efficiently ? My naive idea: 1. define a unit cell with two vertex (lower and upper site) plus three edges (two horizontal+one vertical): <UNITCELL name="ladderCell" dimension="1"> <VERTEX type="0"/> <VERTEX type="1"/> <EDGE type="0"> <SOURCE vertex="0" offset="0"/> <TARGET vertex="0" offset="1"/> </EDGE> <EDGE type="1"> <SOURCE vertex="0" offset="0"/> <TARGET vertex="1" offset="0"/> </EDGE> <EDGE type="2"> <SOURCE vertex="1" offset="0"/> <TARGET vertex="1" offset="1"/> </EDGE> </UNITCELL> 2. The two-leg ladder is then a chain of such cells: <LATTICEGRAPH name = "my open two leg ladder"> <FINITELATTICE> <LATTICE ref="chain lattice"/> <EXTENT dimension="1" size ="L"/> <BOUNDARY type="open"/> </FINITELATTICE> <UNITCELL ref="ladderCell"/> </LATTICEGRAPH> 3. Finally I modify the model hamiltonian including the two different chemical potentials defined as parameters: <SITETERM type="0" site="i"> -mu0*n(i) </SITETERM> <SITETERM type="1" site="i"> -mu1*n(i) </SITETERM> When I execute dmrg, the code gets stuck at "parsing task files ..." Could you please help me? Thank you. My best regards, Giuliano

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Re: [ALPS-users] Gauge fields in ALPS
by Alex Petrescu 21 Feb '13

21 Feb '13

Hi Matthias, Thanks for your reply. Below is the simplest implementation that I could cook up with free spinless fermions on two sites with *directed* bonds. The output of sparsediag, including the error, is -------------------------------------------------------------------------- parsing task files ... Starting task 1. Quantumnumber N going from 0 to 2 with increment 1 Cannot evaluate expression t# * 1 * 1 -------------------------------------------------------------------------- My short source is attached below. I hope that it's a quick task to figure out what is wrong with the implementation. Thanks in advance, Alex Alexandru Petrescu / Physics Department, Yale University Code attachment In <alps-dir>/lib/xml/lattices.xml I added ------------------------------------------------------------------------ <GRAPH name="my 2-site" vertices="2"> <EDGE source="1" target="2" type="1"/> <EDGE source="2" target="1" type="2"/> </GRAPH> ------------------------------------------------------------------------- In <alps-dir>/lib/xml/models.xml, ------------------------------------------------------------------------ <HAMILTONIAN name="free spinless fermions with bondterm type"> <PARAMETER name="mu" default="0"/> <PARAMETER name="t" default="1"/> <BASIS ref="spinless fermion"/> <SITETERM site="i"> <PARAMETER name="mu#" default="mu"/> -mu#*n(i) </SITETERM> <BONDTERM type="1" source="i" target="j"> <PARAMETER name="t#" default="t"/> -t#*(cdag(i)*c(j)+cdag(j)*c(i)) </BONDTERM> <BONDTERM type="2" source="i" target="j"> <PARAMETER name="t#" default="t"/> -t#*(cdag(i)*c(j)+cdag(j)*c(i)) </BONDTERM> </HAMILTONIAN> ------------------------------------------------------------------------- The parameter file is LATTICE="my 2-site"; ------------------------------------------------------------------------- MODEL="free spinless fermions with bondterm type" NUMBER_EIGENVALUES = 1 CONSERVED_QUANTUMNUMBERS="N" MEASURE_ENERGY = true t = 3.0; V = 0.0; {mu=0.00} -------------------------------------------------------------------------- If instead "spinless fermions" with V=0 are used in the parameter file, sparsediag works, but all energies come out to be 0.

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Gauge fields in ALPS
by Alex Petrescu 17 Feb '13

17 Feb '13

Hello, Is it possible to implement gauge fields for the lattice models? More explicitly, can one define: - bond operators which are a function of the position of the source and target sites - bond operators which are a function of the order in which the source and target sites are specified (say the source site is of type 1, and the target site is of type 2, then there should be a phase Exp[i phi], and conjugate if the source is of type 2 and target of type 1.) Thanks for your answers, Alex

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How to use the hybridization expansion impurity solver libraries?
by backes＠th.physik.uni-frankfurt.de 13 Feb '13

13 Feb '13

Dear all, right now I'm working on a LDA+DMFT code and want to use the Hybridization Impurity Solver from the ALPS package. I have two questions regarding the implementation of the Impurity solver and would be very glad if you could provide me with some guidiance: My first question is, what is the best way to implement the impurity solver in a C++ code? What I've done so far is the following: I'm using the newest ALPS code version 2.1.1-r6176. By modifying the CMakeLists.txt files I compiled the code from the hybridization2 folder into a static library libhybridization_impl2.a which I planned to use. I included the impurity.h header file in my code and added the following Include- and Library-paths into my makefile: -L$(ALPS_DIR)/alps/src/boost -lboost \ -L$(ALPS_DIR)/alps/src/alps -lalps \ -L$(ALPS_DIR)/alps/applications/dmft/qmc -lhybridization_impl2 \ -L$(HOME)/local/lib/hdf5 -lsz \ -L$(HOME)/GotoBLAS2/current -lgoto2 \ -L/usr/lib/openmpi/lib -lmpi -lmpi_cxx \ -L/opt/intel/Compiler/11.1/046/lib/intel64 -limf -lirc -lifcore -lsvml -I$(ALPS_DIR)/alps/src \ -I$(ALPS_DIR)/alps/src/alps/ngs/lib \ -I$(ALPS_DIR)/alps/applications/dmft/qmc \ -I$(ALPS_DIR)/alps/applications/dmft/qmc/hybridization2 \ -I/usr/lib/openmpi/include As a reference I used the main.C file in the hybridization2 folder. Therefore, calling the impurity solver looks like this: int main(int argc, char *argv[]) { ... #ifdef USE_MPI boost::mpi::environment env(argc, argv); boost::mpi::communicator world; #endif ... //Do all initalization, generate intial Weiss-Field/Bath-GF //Enter DMFT loop while(!converged) { //Save Weiss-Field/Bath-GF into HDF5 file for the solver ... alps::mcoptions options(argc, argv); if (options.valid) { alps::parameters_type<hybridization>::type parms(alps::hdf5::archive(options.input_file, "r")); alps::parallel<hybridization> s(parms, world); if(options.time_limit!=0) throw std::invalid_argument("time limit is passed in the parameter file!"); if(!parms.defined("MAX_TIME")) throw std::runtime_error("parameter MAX_TIME is not defined. How long do you want to run the code for? (in seconds)"); s.run(boost::bind(&stop_callback, boost::posix_time::second_clock::local_time() + boost::posix_time::seconds((int)parms["MAX_TIME"]))); if (world.rank()==0) { alps::results_type<hybridization>::type results = collect_results(s); save_results(results, parms, options.output_file, "/simulation/results"); } ... //Read the results from the output file and convert //the Impurity GF from Legendre representation to //Matsubara representation. } //Do remaining DMFT steps: //Get Selfenergy //Hilbert-Transformation //Get new bath GF //check convergence } //end of DMFT loop } Everything seems to work quite well but I would also like to use the functions that print information about the percentage of work done and I want to feed and read my data directly in/to the impurity solver without writing them into a file. So the way I currently do it is far away from optimal. Can you give me a general advice on how you intended the impurity solver to be used in a C++ code? Another problem that I have, but want to adress after I resolved my first question, is that the GF from the Impurity Solver is not decaying like 1/w_n but with some factor ~ 1/1.5w_n. I'm using the Legendre representation of the GF and transform it back for further use in the DMFT cycle. Do you know a possible reason for this? Is this simply caused by too few Sweeps or Legendre coefficients? I'd greatly appreciate your help. Sincerely, Steffen Backes

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