I was able to solve this using: ----------------------------------------- for x in kwant_model.sites(): x.family.norbs=1 for x in lead.sites(): x.family.norbs=1 kwant_model.attach_lead(lead) kwant_model.attach_lead(lead.reversed()) kwant_sys = kwant_model.finalized() ----------------------------------------------------- Regards, Eleni Quoting elchatz@auth.gr:

Hello again,

I am having trouble defining the nomber of orbitals in the current operator for an infinite system.

--------------------------- model = tbmodels.Model.from_wannier_files( hr_file='seedname_hr.dat', wsvec_file='seedname_wsvec.dat', xyz_file='seedname_centres.xyz', win_file='seedname.win' )

def shape(p): x, y, z = p return -6*model.uc[0][0] < x < 6*model.uc[0][0] and -1*model.uc[1][1] < y < 1*model.uc[1][1] and 0 < z < 30

def lead_shape(p): x, y, z = p return -3*model.uc[0][0] < x < 1*model.uc[0][0] and -1*model.uc[1][1] < y < 1*model.uc[1][1] and 0 < z < 30

lattice = model.to_kwant_lattice()

for x in lattice.sublattices: x.norbs=1

kwant_model = kwant.Builder() kwant_model[lattice.shape(shape, (0, 0, 15))] = 0 model.add_hoppings_kwant(kwant_model)

sym_lead = kwant.TranslationalSymmetry(lattice.vec((-4, 0, 0))) lead = kwant.Builder(sym_lead) lead[lattice.shape(lead_shape, (0, 0, 15))] = 0 model.add_hoppings_kwant(lead)

kwant_model.attach_lead(lead) kwant_model.attach_lead(lead.reversed())

kwant_sys = kwant_model.finalized() psi = kwant.wave_function(kwant_sys)(0)[0] J = kwant.operator.Current(kwant_sys) current = sum(J(p) for p in psi)

ValueError Traceback (most recent call last) <ipython-input-37-4d2b8ea6f8e4> in <module>() 1 psi = kwant.wave_function(kwant_sys)(0)[0] ----> 2 J = kwant.operator.Current(kwant_sys) 3 current = sum(J(p) for p in psi) 4

kwant\operator.pyx in kwant.operator.Current.__init__()

kwant\operator.pyx in kwant.operator._LocalOperator.__init__()

ValueError: Number of orbitals not defined. Declare the number of orbitals using the `norbs` keyword argument when constructing the site families (lattices).

for x in lattice.sublattices: print(x.norbs)

1 1 1 1 1 1 1 1 1.... ------------------------------------------------

This worked for a closed system.

Regards,

-- Dr. Eleni Chatzikyriakou Computational Physics lab Aristotle University of Thessaloniki elchatz@auth.gr - tel:+30 2310 998109

-- Dr. Eleni Chatzikyriakou Computational Physics lab Aristotle University of Thessaloniki elchatz@auth.gr - tel:+30 2310 998109