Hi, Fernando,

Assuming that you use DMRG simulation since you specify 'MAXSTATES'.


(2014/06/12 0:10), Fernando Iemini wrote:

I've using the ''alternative fermion Hubbard'' model, with open boundary
conditions, and analyzing its single-particle correlations, <cdag_up:c_up>.
I'm not being able however to compute these observables for larger
lattices, e.g., L=~160. I'm getting a "segmentation fault" message, does
anybody know why is happening this error, maybe due to memory? If so, what
would be good parameters in order to avoid it?

Here is the script i'm using:

LATTICE="open chain lattice"
MODEL="alternative fermion Hubbard"
CONSERVED_QUANTUMNUMBERS="N,Sz,Nup,Ndown"
N_total=160
Sz_total=0
Nup_total=80
Ndown_total=80
mu=0
t=1
NUMBER_EIGENVALUES=1
L=160
MAXSTATES=100
MEASURE_CORRELATIONS[cdag_up c_up]="cdag_up:c_up"
{U = 9.000000e-01,V=5.500000e-01,TRUNCATION_ERROR=1e-7}

This is memory issue. The problem is that 'MEASURE_CORRELATIONS'
collects all pair sites. Observing ~10000 measurements costs too much
memory.

Not tested, but I believe that you can avoid this issue by tweaking
models.xml and lattices.xml. Change the name of some specific operator
and just calculating between them.

--
Ryo IGARASHI, Ph.D.
rigarash@issp.u-tokyo.ac.jp
tel: 04-7136-5343, fax: 04-7136-3441
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