March 2013 - Comp-phys-alps-users

compling alps
by Mateusz Łącki 10 Mar '13

10 Mar '13

Dear All, I would like to as bout compiling alps again. This time I have problem with: [ 75%] Building Fortran object applications/dmrg/tebd/CMakeFiles/tebd.dir/core/Hdf5Interface.f90.o more preciselt the error is "module gnerated with wrong version of a compiler" The command that fails is: ifort CMakeFiles/tebd.dir/core/Hdf5Interface.f90.o -DBOOST_ALL_NO_LIB=1 -DBOOST_ALL_DYN_LINK=1 -openmp -O3 -I/usr/lib/openmpi/include -I/usr/lib/openmpi/include/openmpi -I/usr/include -I/home/lacki/opt/libhdf5-1.8.10-intel/include -I/home/lacki/opt/python-2.7.3/lib/python2.7/site-packages/numpy/core/include -I/home/lacki/opt/python-2.7.3/include/python2.7 -I/home/lacki/alps/customs/src -I/home/lacki/alps/customs/alps-2.1.1-r6176-src-with-boost/alps/src -I/home/lacki/alps/customs/alps-2.1.1-r6176-src-with-boost/boost -c /home/lacki/alps/customs/alps-2.1.1-r6176-src-with-boost/alps/applications/dmrg/tebd/core/Hdf5Interface.f90 In fact in both -I/home/lacki/opt/libhdf5-1.8.10-intel/include and -I/usr/include there is Hdf5 module but in -I/usr/include another version is present. Somehow this version takes precedence. Is there way to overcome it? On a previous computer no version of Hdf5 was installed in -I/usr/include. The solution seemes to be just swapping -I/home/lacki/opt/libhdf5-1.8.10-intel/include and -I/usr/include. my INCLUDE is /opt/intel/Compiler/13.0/composer_xe_2013.1.117/mkl/include:/home/lacki/opt/libhdf5-1.8.10-intel/include Kind Regards, Mateusz

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local magnetization in DMRG with preodic boundaries
by Emanuele Levi 10 Mar '13

10 Mar '13

Dear ALPS developers and users, I am running a DMRG simulation with alps on a Heisenberg chain with periodic boundary conditions. My parameter file is 'LATTICE' : "chain lattice", 'MODEL' : "spin", 'CONSERVED_QUANTUMNUMBERS' : 'Sz', 'L' : 24, 'Sz_total' : 0, 'Jxy' : 1, 'Jz' : 3, 'SWEEPS' : 4, 'NUM_WARMUP_STATES' : 100, 'MAXSTATES' : 100, 'NUMBER_EIGENVALUES' : 1, 'MEASURE_LOCAL[Local magnetization]' : 'Sz' In this regime I know the ground state has null global magnetization. As I am considering periodic boundaries, my results should be translationally invariant, and I should get a null local magnetization as well. Strangely enough though, when I check the local magnetization (last line of parameter file), I get a non-zero value. If I consider small L I find a local magnetization of the order E-7, which means practically 0. But when I grow the chain, this number rises, and in the case I am attaching is alternating, and of order 0.0275. How could it be possible? Are not periodic boundary conditions enough to constrain to impose invariance under translation in the final state? Moreover it really looks like considering more states and sweeping more doesn't help. Thanks in advance for any help. Kindest regards. -- Emanuele Levi emanuele.levi(a)gmail.com

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total momentum in DMRG
by Emanuele Levi 09 Mar '13

09 Mar '13

Dear ALPS developers and users, in considering a periodic spin system, is there a way in ALPS to fix the total momentum from the beginning, or measure it? Many thanks. Kindest regards. -- Emanuele Levi emanuele.levi(a)gmail.com

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constraint in Kondo lattice model
by Bo-Nan JIANG 09 Mar '13

09 Mar '13

Hi,all If I set the constraint quantum number to be Sz in the Kondo lattice model, but do not specify which type it is(spin or fermion), so does it mean that the conserved quantum number is the total Sz of Sz_spin + Sz_fermion? And if I set the type of constraint to be spin or fermion, in other orders, type="1" or type="0", then the conserved quantum number is the total Sz of spin or fermion? While for quantum number N which only belongs to type="0" alternative fermion (SITEBASIS "spin" does not have it), then whether I specify the type or not in <CONSTRAINT >, the conserved quantum number shall always be the the total number of fermion.This is my understanding of this part of ALPS, and am I right? Bo-Nan -- Stay foolish,Stay hungry.

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matrices as alps input
by Mateusz Łącki 08 Mar '13

08 Mar '13

Dear All, I am writing again as it seems taht my email got forgotten. I would like to ask again if it is possible to define local operators somehow as matrices (and giving matrices as a table of numbers). That is instead if defining rule that n^2 operator should have matrix element n*n i would liket o be able to say that: T= 1 |1><1> + 6.78 |2><2| + 78.2 |3><3| +... for diagonal operator (and possibly also for nondiagonal operators). Up to now the onyl way i thought was to define a kronecker delta operator (in the code, recompile) which would be used to define: KD(1,n) + KD(2,n)+6.78 +78.2 DK(3,n) for the diagonal operators... Regards, Mateusz

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Fwd: Setting Constraint
by Ali Beyramzadeh Moghadam 07 Mar '13

07 Mar '13

Dear ALPS Member, I am trying to run ALPS DMRG to calculate gap for a spin system on 3-chain lattice. My energy eigenvalue is degenerate and I am trying to divide the system to different sector using the constraint. I want to set an eigenvalue of one operator to have a specific value. My problem is the operator which divide my Hilbert space to different sector is not local and depends on several site. I am wondering if I can do that with constraint. Should I define a new quantum number other than Sz? Thank you for your help, Best, Ali

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Splus and Sminus in SITEBASIS fermion
by Bo-Nan JIANG 06 Mar '13

06 Mar '13

Hi,all we all know, for the angular momentum, the operator matrix element of Jplus is sqrt(J*(J+1)-Jz(Jz+1)) and for Jminus, it is sqrt(J*(J+1)-Jz(Jz-1)). Just as ALPS defines in SITEBASIS "spin". So, it is straightforward that the spin-1/2 fermion with S=1/2, the matrix elements of Splus and Sminus shall be sqrt((1/2)*(1/2+1)-(-1/2)(-1/2+1))=1 and sqrt((1/2)*(1/2+1)-1/2(1/2-1))=1 respectively. If I am right, then why you guys define the matrix element of Splus and Sminus in SITEBASIS "fermion" and "alternative fermion" all equal to 1/2? Bo-Nan -- Stay foolish,Stay hungry.

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edges in ALPS
by Bo-Nan JIANG 06 Mar '13

06 Mar '13

Hi,all Can I define an edge in ALPS but do not define the any bond operator depending on it? For example, I define the type 0 ,1,2 edges, but only type 0,1 bond operator. I know someone will say since you do not use the type 2 edge, then why you define it. OK, as my argument, I just want to know whether it works. So, what is the answer? Bo-Nan -- Stay foolish,Stay hungry.

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input file for the imaginary frequency data for maxent code
by Viveka Singh 05 Mar '13

05 Mar '13

Dear all, I am trying to use the maxent code from ALPS. In the document hybdoc.pdf, it is being suggested that "it helps to continue the self-energies instead of the Green's functions". But the CT-QMC hybridization code only returns the imaginary frequency self-energy, and it does not mention error associated with it. While it is suggested that one should use data with error bars for the analytic continuation. In the sample parameter file in the hybdoc.pdf, even though DATASPACE=frequency, the data points(X_i) are taken as real numbers. In general it should be a complex numbers. Can somebody clarify this as to how to input the self-energy (complex number) and what should one do about the errors associated with the self-energy? I tried to give input as X_i=(0.5,0.5), but parameter2xml gives error when it tries to convert the input file to xml format. It says - Caught exception: parameter parse error at "{ PARTICLE_HOLE_SYMMETRY = 1 X_0". So, can someone send some sample input file for the analytic continuation of imaginary frequency data (complex numbers) to the real frequency. With best regards, Viveka Nand Singh

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Crash of looper using custom lattice
by Bertaina Sylvain 05 Mar '13

05 Mar '13

Hi all, It try to use customs lattices with looper but it seems to crash. I use an easy one to start , a simple closed chain with 16 spins. The calculation work with dirlooper_sse (but take a long time and have very few options) but using "loop" algorithm it crash immediately here is the lattice : <LATTICES> <GRAPH name = "chain lattice 16" dimension="1" vertices="16" edges="16"> <EDGE source="1" target="2" id="1" type="0" /> <EDGE source="2" target="3" id="2" type="0" /> <EDGE source="3" target="4" id="3" type="0" /> <EDGE source="4" target="5" id="4" type="0" /> <EDGE source="5" target="6" id="5" type="0" /> <EDGE source="6" target="7" id="6" type="0" /> <EDGE source="7" target="8" id="7" type="0" /> <EDGE source="8" target="9" id="8" type="0" /> <EDGE source="9" target="10" id="9" type="0" /> <EDGE source="10" target="11" id="10" type="0" /> <EDGE source="11" target="12" id="11" type="0" /> <EDGE source="12" target="13" id="12" type="0" /> <EDGE source="13" target="14" id="13" type="0" /> <EDGE source="14" target="15" id="14" type="0" /> <EDGE source="15" target="16" id="15" type="0" /> <EDGE source="16" target="1" id="16" type="0" /> </GRAPH> </LATTICES> here is the python script : ------------------------------------------------------ #! /usr/bin/python import pyalps import matplotlib.pyplot as plt import pyalps.plot #prepare the input parameters parms = [] for t in [0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.25, 1.5, 1.75, 2.0]: parms.append( {'LATTICE_LIBRARY' : 'my_lattice.xml', 'LATTICE' : chain lattice 16', 'MODEL' : 'spin', 'local_S0' : '.5', 'T' : t, 'J0' : 1 , 'THERMALIZATION' : 5000, 'SWEEPS' : 50000, 'ALGORITHM' : "loop" } ) #write the input file and run the simulation input_file = pyalps.writeInputFiles('parmcustom',parms) pyalps.runApplication('loop',input_file) #load the susceptibility and collect it as function of temperature T data = pyalps.loadMeasurements(pyalps.getResultFiles(prefix='parmcustom'),'Susceptibility') susceptibility = pyalps.collectXY(data,x='T',y='Susceptibility') #make plot plt.figure() pyalps.plot.plot(susceptibility) plt.xlabel('Temperature $T/J$') plt.ylabel('Susceptibility $\chi J$') plt.ylim(0,0.22) plt.title('Quantum Heisenberg chain') plt.show() ----------------------------------- I hope someone can help me with regards -- Sylvain Bertaina Chargé de recherche IM2NP - UMR 7334 CNRS Faculté des Sciences et Techniques Avenue Escadrille Normandie Niemen - Case 162 - 13397 Marseille Cedex 20 (France) Tel: +33 (0) 4 91 28 27 66 Fax: +33 (0) 4 91 28 87 75

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