Dear all,

  I am trying new Kwant 1.3 features on a very simple example of graphene monolayer, and, apart from a standard well-working code I add:

for x in sys.sites(): x.family.norbs=1 for x in leadxp.sites(): x.family.norbs=1 for x in leadxm.sites(): x.family.norbs=1 (to avoid norbs not defined error)

...

J_0 = kwant.operator.Current(sys) wf = kwant.solvers.default.wave_function(sys, energy=0.01, args=[phi,chempot,0]) psi=wf(1) current = J_0(psi)  

I get the following suspicious message:  The size of the file /home/sergey/.local/lib/python3.6/site-packages/kwant/operator.cpython-36m-x86_64-linux-gnu.so is 2734 KB. Do you really want to load it?

After answering yes, I get the error message, caused by current = J_0(psi) : 

"The debugged program raised the exception unhandled ValueError "vector is incorrect shape" File: /home/sergey/.local/lib/python3.6/site-packages/kwant/operator.cpython-36m-x86_64-linux-gnu.so, Line: 529

Break here?"

Could anyone guess, what goes wrong?

N.B. I have installed Kwant with a command pip3 install kwant

Thanks,

Sergey