- Comp-phys-alps-users - lists.phys.ethz.ch

2D Heisenberg model with open boundary in one spatial direction
by Fu-Jiun Jiang ITP 26 Jan '09

26 Jan '09

Hello all I think I should try to make my quick questions more precise (hence slightly more interesting). For a 2D Heisenberg model with open boundary in one spatial direction, can one measure the spin-spin correlations as well as the on-site magnitization as functions of distance from the open boundary using ALPS without modifying the codes dramatically? Thanks in advance! Sincerely, FJ

4 8

follow-up on GCC 4.3 bug for spinmc_factory
by Jeff Hammond 26 Jan '09

26 Jan '09

I discovered that the problem with g++ 4.3 segfaulting on spinmc_factory has been logged with GCC Bugzilla - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38369 - and that the problem persists in 4.3.3, which I discovered on my own prior to finding that bug report. According to the bug report, GCC 4.4.0 corrects whatever the problem is, so ALPS spinmc users reliant upon GCC might want to skip from GCC 4.2 to 4.4 (whenever it appears) or resign themselves to the poor performance of "-O0" with 4.3 as reported previously. Jeff -- Jeff Hammond The University of Chicago http://home.uchicago.edu/~jhammond/

2 1

Re: [ALPS-users] one solution to compilation issues with GCC
by Tadeusz Wasiutynski 24 Jan '09

24 Jan '09

On Fri, 23 Jan 2009 12:00:04 +0100, comp-phys-alps-users-request wrote > 8. Re: one solution to compilation issues with GCC (Matthias > Troyer) > > ---------------------------------------------------------------------- > > > Message: 7 > Date: Thu, 22 Jan 2009 10:59:55 -0600 > From: Jeff Hammond <jeff.science(a)gmail.com> > Subject: Re: [ALPS-users] one solution to compilation issues with GCC > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: > <96f4bb620901220859g1561bd29uc938624e70e5e502(a)mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > I had no trouble compiling ALPS 1.33 with GCC 4.3.1 and Boost 1.37, > and yes, it was much faster to do this than to install GCC. > > Jeff > > On Thu, Jan 22, 2009 at 9:36 AM, Matthias Troyer > <troyer(a)phys.ethz.ch> wrote: > > > > Thanks for your help! It might be easier to switch Boost versions than > > compiler. Could you or someone else with the same problem try to download > > Boost 1.37.0 and see whether that also solves the problem? > > > > Matthias > > > > -- > Jeff Hammond > The University of Chicago > http://home.uchicago.edu/~jhammond/ > > ------------------------------ > > Message: 8 > Date: Thu, 22 Jan 2009 10:53:04 -0800 > From: Matthias Troyer <troyer(a)phys.ethz.ch> > Subject: Re: [ALPS-users] one solution to compilation issues with GCC > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: <BF5A683A-B460-4E06-9E27-67260C11C400(a)phys.ethz.ch> > Content-Type: text/plain; charset=US-ASCII; format=flowed > > On 22 Jan 2009, at 08:59, Jeff Hammond wrote: > > > I had no trouble compiling ALPS 1.33 with GCC 4.3.1 and Boost 1.37, > > and yes, it was much faster to do this than to install GCC. > > > > Jeff > > Thanks, I'll add a note to the Wiki! > > Matthias > > End of Comp-phys-alps-users Digest, Vol 34, Issue 7 > *************************************************** Indeed the compilation of ALPS-1.3.3 goes smoothly with gcc-4.3.1 and boost-1.37. Unfortunately alps-applications compilation breaks on spinmc.factory while was not the case with older gcc. All other prerequisities but lp_solve come in the system. Any suggestions? Shall we compare all the components incl kernel? Tadeusz

2 1

Re: [ALPS-users] uniform susceptibility
by Tadeusz Wasiutynski 24 Jan '09

24 Jan '09

On Sat, 24 Jan 2009 12:00:02 +0100, comp-phys-alps-users-request wrote > 4. Re: uniform susceptibility (Matthias Troyer) > Message: 4 > Date: Fri, 23 Jan 2009 09:21:06 -0800 > From: Matthias Troyer <troyer(a)phys.ethz.ch> > Subject: Re: [ALPS-users] uniform susceptibility > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: <71F122F5-D527-4E3A-B308-8A86A23FD70C(a)phys.ethz.ch> > Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes > > On 23 Jan 2009, at 08:58, Tadeusz Wasiutynski wrote: > >> > > Thank you for prompt answer. There is still something unclear for > > me. When > > running spinmc Ising model with say L=8 and T=1, square lattice, > > update > > cluster, sweeps 100000 I get: > > Magnetization^2 0.99862084 > > |Magnetization| 0.999285325 > > Susceptibility 63.911734 > > So it looks like Susceptibility=N * Magnetization^2 > > On the other hand given susceptibility at Tc scales very well with > > size. > > Where do I make mistake? > > The "susceptibility" is measuredas N*Magnetizatio^2/T. Since T=1 > here, you get what you observe > > Matthias > > ------------------------------ > In the other words it is not (<Magnetization^2>-<|Magnetization|>^2)/T as one could think. tadeusz

1 0

Re: [ALPS-users] uniform susceptibility
by Tadeusz Wasiutynski 23 Jan '09

23 Jan '09

On Fri, 23 Jan 2009 12:00:04 +0100, comp-phys-alps-users-request wrote > 2. uniform susceptibility (Tadeusz Wasiutynski) > Message: 2 > Date: Thu, 22 Jan 2009 12:55:44 +0100 > From: "Tadeusz Wasiutynski" <Tadeusz.Wasiutynski(a)ifj.edu.pl> > Subject: [ALPS-users] uniform susceptibility > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: <20090122115137.M49749(a)ifj.edu.pl> > Content-Type: text/plain; charset=iso-8859-2 > > hello, > I try to understand all examples in alps-applications. How can I > figure out what exactly is in the output as "uniform susceptibility" > (say in Ising) and why it is not simply <M2>-<M>2? In which part of > the code it is hidden? Tadeusz > > ------------------------------ > > Message: 4 > Date: Thu, 22 Jan 2009 23:10:11 +0900 (JST) > From: Synge Todo <wistaria(a)comp-phys.org> > Subject: Re: [ALPS-users] uniform susceptibility > To: comp-phys-alps-users(a)phys.ethz.ch, Tadeusz.Wasiutynski(a)ifj.edu.pl > Message-ID: <20090122.231011.245963879.wistaria(a)comp-phys.org> > Content-Type: Text/Plain; charset=us-ascii > > If 'M' means the total uniform magnetization (i.e. M = \sum s_i^z), > the uniform susceptibility and <M2>-<M>2 differ by the factor \beta/N > (\beta = 1/T and N the number of sites). If 'M' is the magnetization > per site (\sum s_i^z / N), then the factor becomes \beta \times N. > > Synge > Thank you for prompt answer. There is still something unclear for me. When running spinmc Ising model with say L=8 and T=1, square lattice, update cluster, sweeps 100000 I get: Magnetization^2 0.99862084 |Magnetization| 0.999285325 Susceptibility 63.911734 So it looks like Susceptibility=N * Magnetization^2 On the other hand given susceptibility at Tc scales very well with size. Where do I make mistake? Tadeusz

2 1

one solution to compilation issues with GCC
by Jeff Hammond 22 Jan '09

22 Jan '09

I was not able to compile ALPS 1.3.3 with GCC 4.3.1 but had no problems once I installed GCC 4.2.4 and compiled with that instead. Hopefully this information will be of use to others who use a Linux distro which ships with GCC 4.3 and subsequently struggle to compile ALPS. The only downside of this solution is that compiling GCC 4.2.4 takes a few hours with the default set of features. Best, Jeff -- Jeff Hammond The University of Chicago http://home.uchicago.edu/~jhammond/

3 6

uniform susceptibility
by Tadeusz Wasiutynski 22 Jan '09

22 Jan '09

hello, I try to understand all examples in alps-applications. How can I figure out what exactly is in the output as "uniform susceptibility" (say in Ising) and why it is not simply <M2>-<M>2? In which part of the code it is hidden? Tadeusz

2 1

depleted lattice
by Brian Keith 21 Jan '09

21 Jan '09

I have two questions on the depleted lattice. I am using the depleted lattice as defined in the lattices.xml that ALPS provides. I would like to run a simulation with the DEPLETION variable set to something extremely small like .0004. Do I need to make the lattice size huge, on the order of 1000's of spins, to ensure that the lattice will have a reasonable chance of getting a hole in it? I will run the simulation on a spin ladder if that makes a difference. I would also like to simulate a lattice where the DEPLETION variable is modified by the number of holes close to it, i.e. I would like to encourage the simulation to form small clusters of these spinless holes. Is this easily done? -- Brian Keith Dept. of Physics Clark University

2 1

Classical Monte Carlo - ground states
by Prsa Krunoslav 21 Jan '09

21 Jan '09

Dear All, I am running a Classical Monte Carlo simulation (spinsim, ALPS v. 1.3) on a certain frustrated magnetic lattice. I am trying to simulate one material's behaviour in low temperature (T/J~0.01). I have made quick and dirty modifications of the spinsim.h in order to extract the actual snapshots of the simulated system. Via snapshots, I am extracting the system's structure factor and calculating the neutron Bragg peak intensities vs. field. My material is complicated and its field properties (and this, after looking at the results seems to be the case with the structure factors, not so with magnetization) may depend on the ground state and the details of the simulation. I have a following question: If I specify the input file like the following: LATTICE="my lattice" LATTICE_LIBRARY="../../lattices.xml" T=0.01 J=-1 THERMALIZATION=100000 SWEEPS=5000000 UPDATE="local" MODEL="Ising" L=100 W=100 {h=0;} {h=1;} {h=2;} what actually happens? Does ths start three simulations that are completely separate (starting from i.e. random values of the ground state before), or it is the same simulation meaning that here the simulation with h=0 finishes, the field is applied to *that* ground state and then the simulation continues for h=1? I seem to need the latter case. I hope my question is clear, if it is not, I can rephrase and add more details. Best and thanks for the great work, Kruno --------------------------------------- Krunoslav Prsa, Ph. D. Student Laboratory for Neutron Scattering Paul Scherrer Institute and ETH-Zürich CH-5232 Villigen PSI, Switzerland tel: +41 56 310 20 91 mob: +41 76 386 17 99 ----------------------------------------

2 1

spin correaltion
by Fu-Jiun Jiang ITP 21 Jan '09

21 Jan '09

Hello all I am new to ALPS, but I found it very useful! I got a quick question regrding the " spin correlation ". For a usual Heisenberg model, the output file reads like (0,0) -- (0,1) .... and so. What dose the first (second) coordinate stand for? I think my question is as follows, namely, for a square lattice, say 10 by 10 lattices, how the coordinates for these lattice sites are arranged in the output file. Thanks in advance. FJ

2 1