from pygra import geometry
g = geometry.honeycomb_lattice() # get the geometry object
h = g.get_hamiltonian() # get the Hamiltonian object
h.get_bands() # compute the band structure

from pygra import geometry
from pygra import scftypes
g = geometry.honeycomb_zigzag_ribbon(10) # create geometry of a zigzag ribbon
h = g.get_hamiltonian() # create hamiltonian of the system
mf = scftypes.guess(h,"ferro",fun=lambda r: [0.,0.,1.])
scf = scftypes.hubbardscf(h,nkp=30,filling=0.5,mf=mf)
h = scf.hamiltonian # get the Hamiltonian
h.get_bands(operator="sz") # calculate band structure

from pygra import specialgeometry
from pygra.specialhopping import twisted_matrix
g = specialgeometry.twisted_bilayer(3)
h = g.get_hamiltonian(mgenerator=twisted_matrix(ti=0.12))
h.get_bands(nk=100)

from pygra import geometry
from pygra import topology
g = geometry.honeycomb_lattice()
h = g.get_hamiltonian()
h.add_rashba(0.3) # Rashba spin-orbit coupling
h.add_zeeman([0.,0.,0.3]) # Zeeman field
c = topology.chern(h) # compute Chern number
print("Chern number is ",c)

from pygra import geometry
from pygra import films
g = geometry.diamond_lattice_minimal()
g = films.geometry_film(g,nz=20)
h = g.get_hamiltonian()
h.get_bands()

from pygra import geometry
from pygra import kdos
g = geometry.honeycomb_lattice()
h = g.get_hamiltonian()
h.add_haldane(0.05)
kdos.surface(h)

from pygra import geometry
g = geometry.honeycomb_zigzag_ribbon(10) # create geometry of a zigzag ribbon
h = g.get_hamiltonian(has_spin=True) # create hamiltonian of the system
h.add_antiferromagnetism(lambda r: (r[1]>0)*0.5) # add antiferromagnetism
h.add_swave(lambda r: (r[1]<0)*0.3) # add superconductivity
h.get_bands() # calculate band structure

from pygra import geometry
from pygra import spectrum
import numpy as np
g = geometry.kagome_lattice()
h = g.get_hamiltonian()
spectrum.multi_fermi_surface(h,nk=60,energies=np.linspace(-4,4,100),
        delta=0.1,nsuper=1)