Hello,
Sometimes QMC worm code (used on Bose-Hubbard) terminates with the following error:
here come first earlier succesful simulations then
...
Created run 85 remote on Host ID: 84
Created run 86 remote on Host ID: 85
Created run 87 remote on Host ID: 86
Created run 88 remote on Host ID: 87
All processes have been assigned
Checking if Simulation 1 is finished: not yet, next check in 120 seconds ( 0% done).
q = -0 state1 = 0 state2 = 0 bond_type = 0
zero matrix element in remove_jump
…
[View More]application called MPI_Abort(MPI_COMM_WORLD, -2) - process 67
Could somebody advice what I can do?
Best regards Kuba
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I was looking into the convergence of the ground state energy in DMRG as a
function of NUMSTATES. For instance, on a 1D chain of spinless fermions with
open boundary conditions at half-filling (L=36, N_TOTAL=12) and interaction
strength V0=4, the ground state energies after 30 sweeps are
M=2 E0 = -8.6661
M=4 E0 = -9.6249
M=8 E0 = -9.7115
M=100 E0 = -9.7133
The truncation error for the M=2 run was just 0.00167, so it is surprising
(to me, at lest) that the energy is off …
[View More]by more than 10 percent. A
discrepancy of 10 percent or more occurs for chains of different lengths and
interaction potentials of different strengths. Doing 100 sweeps instead of
30 has no effect on the first 5 digits of the M=2 results. Nor does
increasing NUM_WARMUP_STATES to 100. One possibility is that the calculation
is getting stuck in a local minimum.
Does the ALPS DMRG routine have any method for avoiding local minima? For
instance, adding a small amount of noise to the calculation to allow
tunneling out of local minima? Even if the results of the above calculations
simply reflect the poor quality of the M=2 wave function, it would still be
useful to know how to handle local minima that might occur in DMRG
calculations.
Jesse
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Dear Alps list,
Greatings from Angola...
I am trying to extract the Green Function and the local magnetization
running the loop code.
I tried into the simplest example..
param file:
LATTICE="open chain lattice"
MODEL="spin"
local_S=1/2
L=10
J=1
INITIAL_SITE=1
THERMALIZATION=15000
SWEEPS=150000
REPRESENTATION="SSE"
MEASURE[Green Function]=true
MEASURE[Correlations]=true
MEASURE[Local Susceptibility]=true
{T=0.05;}
the simulation runs in 1m but there is no output for either Green's
…
[View More]Funtion or Local Magnetization...
Am I doing something terrible wrong or the looper code is not given
these measures?
Thanks in Advance
João
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