Sorry,the formatting on the page is out of order, so I send the email again.
Dear Rongyang,
Thank you for your help and sugggestions. I will pay attention to the
details when I use ALPS and try to use ALPS MPS library to do DMRG
simulation.
Though the parameter works, I still have problems.
i) The ground state energy is E0= -11.1895. But I have checked it by matlab
and quspin using ED method, the results calculated by the two softwares are
the same E0=-10.0499. Then I asked my friend to calculate the same model
with the same parameters by itensor and he also got E0=-10.0499. I suspect
that there is still a problem exist in my XML files.
ii) I try to use ALPS MPS. And I will read the paper about ALPS MPS for
more details later.When I use open chain lattice, it can run. But when I
use 2 band sublattice open chain lattice, it shows
---------------------------------------------------
Running task 1.
This binary contains symmetries: nu1
MAQUIS repo r4143
Temporary storage is disabled
Restoring state.
Will start again at site -1 in sweep 30
MPS initialization has finished...
Measurements.
Measuring n
Energy: 1
This task took 0.313551 seconds.
Finished with everything.
------------------------------------------------
Why?
iii) I want to write the tunneling rate t as a function of the position.
--------------------------------------------------
import pyalps
import numpy as np
parms = [ {
#'LATTICE' : "2 band sublattice open chain lattice",
'LATTICE' : "open chain lattice",
'LATTICE_LIBRARY': './lattices.xml',
'MODEL' : "sublattice boson Hubbard",
'MODEL_LIBRARY': './models.xml',
'CONSERVED_QUANTUMNUMBERS' : 'N',
'T' : 0,
't0' : 3-2*np.cos(x*np.pi+np.pi),
#'t1' : 1,
'SWEEPS' : 30,
'MAXSTATES' : 300,
'init_state' : "thin" ,
'NUMBER_EIGENVALUES' : 1,
'L' : 4,
'Nmax' : 1,
'N_total' : 2,
'MEASURE_LOCAL[n]' : 'n'
} ]
input_file = pyalps.writeInputFiles('ssh',parms)
res = pyalps.runApplication('mps_optim',input_file,writexml=True)
------------------------------- Then I got the error:
---------------------------------------------------
Traceback (most recent call last):
File "./ssh.py", line 12, in <module>
't0' : 3-2*np.cos(x*np.pi+np.pi),
NameError: name 'x' is not defined
-------------------------------------------------- So how can I define the
parameter when it is changed by site position?