Comp-phys-alps-users

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1248 discussions

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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Re: [ALPS-users] Comp-phys-alps-users Digest, Vol 84, Issue 1
by Bo-Nan JIANG 04 Mar '13

04 Mar '13

Hi,Matthias Maybe the reason is that I am running ALPS in the windows XP operating system. So, the following question is if I program ALPS in XML, how to make it run in a windows operating system? Oh, by the way, though some function of ALPS is disable in the windows, the ED and DMRG are good, so let's just focus on these two. Bo-Nan 2013/3/3 <comp-phys-alps-users-request(a)lists.phys.ethz.ch> > Send Comp-phys-alps-users mailing list submissions to > comp-phys-alps-users(a)lists.phys.ethz.ch > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.phys.ethz.ch/listinfo/comp-phys-alps-users > or, via email, send a message with subject or body 'help' to > comp-phys-alps-users-request(a)lists.phys.ethz.ch > > You can reach the person managing the list at > comp-phys-alps-users-owner(a)lists.phys.ethz.ch > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Comp-phys-alps-users digest..." > > > Today's Topics: > > 1. how to check a lattice graph in python (Bo-Nan JIANG) > 2. Re: how to check a lattice graph in python (Matthias Troyer) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 3 Mar 2013 15:58:26 +0800 > From: Bo-Nan JIANG <bonanjiang(a)gmail.com> > To: "comp-phys-alps-users(a)lists.phys.ethz.ch" > <comp-phys-alps-users(a)lists.phys.ethz.ch> > Subject: [ALPS-users] how to check a lattice graph in python > Message-ID: > < > CADqUQBO4onmxZyN-g6WDUCc8-GO9q-GByYA5G55SjHonj0sYYg(a)mail.gmail.com> > Content-Type: text/plain; charset="gb2312" > > Dear all, > It is well known that to check a lattice graph in Linux, I shall type > "printgraph". But, the question is when I program in the IDLE of python, > how can I realize the same function? > > ?? > > -- > Stay foolish,Stay hungry. >

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Vertex,edge and operator
by Bo-Nan JIANG 04 Mar '13

04 Mar '13

Hi,all This is my interpretation of the relationship between vertex, edge and operator. Am I right? Considering 1D Kondo-Heisenberg model, for example: (1) I shall have two types of vertices - spin and fermion; (2) Three types of edges - fermion to fermion, fermion to spin and spin to spin (considering superexchange interaction between spins); (3) For operators, I shall have - type0 fermion_hop(i,j) related to fermion to fermion edge, type1 exchange(i,j) related to fermion to spin (Kondo-exchange interaction) and type2 exchange(i,j) (superexchange); If I am right, does that mean the number of types of bond operators should be the same as the number of types of edges defined in the unitcell? The other question is: in the unitcell of this simple 1D Kondo-Heisenberg model, I have two-type vertices and three different types of edges, but I do not define the coordinates as your online example "A complex example" in section "How to specify graphs corresponding to a lattice with a unit cell", then is the unitcell which I define 1D or 2D? I think it is 2D, am I right? Bo-Nan -- Stay foolish,Stay hungry.

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how to check a lattice graph in python
by Bo-Nan JIANG 03 Mar '13

03 Mar '13

Dear all, It is well known that to check a lattice graph in Linux, I shall type "printgraph". But, the question is when I program in the IDLE of python, how can I realize the same function? 伯楠 -- Stay foolish,Stay hungry.

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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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