May 2012 - Comp-phys-alps-users - lists.phys.ethz.ch

HELP DMRG --time-limit
by User1 Alps 08 May '12

08 May '12

Hello All, I have some trouble about running dmrg program with command line options. (I am using ALPS 1.3.5 and alps-applications-1.3.5.) For example, I typed "./dmrg --time-limit 10 myjob.in.xml" for making checkpoint in 10 seconds. However, my prgram does not stop at the scheduled time. best regards Tokuro Shimokawa Kobe University, Japan

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QMC worm code and green function
by Žiga Osolin 07 May '12

07 May '12

Hi All, I have started working on my diploma project, Hubbard model with impurities. It would be really helpful if I could measure green function, but apparently MEASURE[Green Function] = True doesn't work. Looking into source code, I found the measurement code commented with a fix me comment in it. Is this feature still not implemented in ALPS worm, and what does the commented code do (and not do)? Secondly, i found out that this green function (zero output actually, with measurement commented) only generated data for (0 -> i). In inhomogeneous system, i would like all pair (i -> j). Are there any plans for this feature? Regards, Žiga Osolin

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Re: [ALPS-users] (no subject)
by Matthias Troyer 02 May '12

02 May '12

For t=0 this is just a classical Ising model and you should thus use a classical MC code, for example the ALPS spinmc code. Matthias Troyer On 2 May 2012, at 08:20, Jianming Cai wrote: > Dear Prof. Troyer, > > I use dir_loopsee to simulate the hardcore boson model on a triangular lattice as follows: > > <HAMILTONIAN name="hardcore boson"> > <PARAMETER name="V0" default="1"/> > <PARAMETER name="V1" default="1"/> > <PARAMETER name="V2" default="1"/> > <PARAMETER name="t" default="0"/> > <PARAMETER name="t0" default="t"/> > <PARAMETER name="t1" default="t"/> > <PARAMETER name="t2" default="t"/> > <PARAMETER name="mu" default="0"/> > <PARAMETER name="cm" default="mu+V0+V1+V2"/> > <BASIS ref="hardcore boson"/> > <SITETERM site="i"> > <PARAMETER name="mu#" default="cm"/> > -mu#*n(i) > </SITETERM> > <BONDTERM source="i" target="j"> > <PARAMETER name="t#" default="0"/> > <PARAMETER name="V#" default="0"/> > -t#*(bdag(i)*b(j)+bdag(j)*b(i)) + V#*n(i)*n(j) > </BONDTERM> > </HAMILTONIAN> > > What I use the parameter t=0, I got the following error message: > > Internal error: size of prob table is zero. > > How could I solve the problem and simulate the model with t equals to 0? > > Many thanks! > > Looking forward to your reply. > > Yours sincerely, > > Jianming >

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