def dispatch(self,
t=(-2.414, -0.168),
beta=(-1.847, -3.077),
a=1.42,
orthogonal=False):
distance = self._obj.distance
da = 0.0005
R = (distance(0, a) + da, distance(1, a) + da, distance(2, a) + da)
def construct(H, ia, atoms, atoms_xyz=None):
idx_t012, rij_t012 = H.geometry.close(ia,
R=R,
atoms=atoms,
atoms_xyz=atoms_xyz,
ret_rij=True)
H[ia, idx_t012[0]] = 0.
H[ia, idx_t012[1]] = t[0] * np.exp(beta[0] * (rij_t012[1] - R[1]))
H[ia, idx_t012[2]] = t[1] * np.exp(beta[1] * (rij_t012[2] - R[2]))
# Define the graphene lattice
C = si.Atom(6, si.AtomicOrbital(n=2, l=1, m=0, R=R[-1]))
graphene = si.geom.graphene(a, C, orthogonal=orthogonal)
# Define the Hamiltonian
H = si.Hamiltonian(graphene)
H.construct(construct)
return H
def from_yaml(cls, file, nodes=()):
""" Parse the yaml file """
from sisl_toolbox.siesta.minimizer._yaml_reader import read_yaml, parse_variable
dic = read_yaml(file, nodes)
element = dic["element"]
tag = dic.get("tag")
mass = dic.get("mass", None)
# get default options for pseudo
opts = NotNonePropertyDict()
pseudo = dic["pseudo"]
opts["logr"] = parse_variable(pseudo.get("log-radii"), unit="Ang").value
opts["rcore"] = parse_variable(pseudo.get("core-correction"), unit="Ang").value
opts["xc"] = pseudo.get("xc")
opts["equation"] = pseudo.get("equation")
opts["flavor"] = pseudo.get("flavor")
define = pseudo.get("define", ('NEW_CC', 'FREE_FORMAT_RC_INPUT', 'NO_PS_CUTOFFS'))
# Now on to parsing the valence shells
orbs = []
for key in dic:
if key not in _shell_order:
continue
# Now we know the occupation is a shell
pseudo = dic[key].get("pseudo", {})
cutoff = parse_variable(pseudo.get("cutoff"), 2.1, "Ang").value
charge = parse_variable(pseudo.get("charge"), 0.).value
orbs.append(si.AtomicOrbital(key, m=0, R=cutoff, q0=charge))
atom = si.Atom(element, orbs, mass=mass, tag=tag)
return cls(atom, define, **opts)
def dispatch(self, t=-2.7, a=1.42, orthogonal=False):
# Define the graphene lattice
da = 0.0005
C = si.Atom(6, si.AtomicOrbital(n=2, l=1, m=0, R=a + da))
graphene = si.geom.graphene(a, C, orthogonal=orthogonal)
# Define the Hamiltonian
H = si.Hamiltonian(graphene)
H.construct([(da, a + da), (0, t)])
return H
def dispatch(self, a=1.42, orthogonal=False):
distance = self._obj.distance
da = 0.0005
R = (distance(0, a) + da, distance(1, a) + da, distance(2, a) + da,
distance(3, a) + da)
# Define the graphene lattice
C = si.Atom(6, si.AtomicOrbital(n=2, l=1, m=0, R=R[-1]))
graphene = si.geom.graphene(a, C, orthogonal=orthogonal)
# Define the Hamiltonian
H = si.Hamiltonian(graphene, orthogonal=False)
t = [(-0.45, 1), (-2.78, 0.117), (-0.15, 0.004), (-0.095, 0.002)]
H.construct([R, t])
return H
def dispatch(self, set='A', a=1.42, orthogonal=False):
distance = self._obj.distance
da = 0.0005
H_orthogonal = True
#U = 2.0
R = tuple(distance(i, a) + da for i in range(4))
if set == 'A':
# same as simple
t = (0, -2.7)
#U = 0.
elif set == 'B':
# same as simple
t = (0, -2.7)
elif set == 'C':
t = (0, -2.7, -0.2)
elif set == 'D':
t = (0, -2.7, -0.2, -0.18)
elif set == 'E':
# same as D, but specific for GNR
t = (0, -2.7, -0.2, -0.18)
elif set == 'F':
# same as D, but specific for GNR
t = [(0, 1), (-2.7, 0.11), (-0.09, 0.045), (-0.27, 0.065)]
H_orthogonal = False
elif set == 'G':
# same as D, but specific for GNR
t = [(0, 1), (-2.97, 0.073), (-0.073, 0.018), (-0.33, 0.026)]
#U = 0.
H_orthogonal = False
else:
raise ValueError(
f"Set specification for {self.doi} does not exist, should be one of [A-G]"
)
# Reduce size of R
R = R[:len(t)]
# Currently we do not carry over U, since it is not specified for the
# sisl objects....
# Define the graphene lattice
C = si.Atom(6, si.AtomicOrbital(n=2, l=1, m=0, R=R[-1]))
graphene = si.geom.graphene(a, C, orthogonal=orthogonal)
graphene.optimize_nsc([0, 1])
# Define the Hamiltonian
H = si.Hamiltonian(graphene, orthogonal=H_orthogonal)
H.construct([R, t])
return H
def dispatch(self, t=-2.7, a=1.42, orthogonal=False):
distance = self._obj.distance
da = 0.0005
R = (distance(0, a) + da, distance(1, a) + da)
def construct(H, ia, atoms, atoms_xyz=None):
idx_t01, rij_t01 = H.geometry.close(ia,
R=R,
atoms=atoms,
atoms_xyz=atoms_xyz,
ret_rij=True)
H[ia, idx_t01[0]] = 0.
H[ia, idx_t01[1]] = t * (a / rij_t01[1])**2
# Define the graphene lattice
C = si.Atom(6, si.AtomicOrbital(n=2, l=1, m=0, R=R[-1]))
graphene = si.geom.graphene(a, C, orthogonal=orthogonal)
# Define the Hamiltonian
H = si.Hamiltonian(graphene)
H.construct(construct)
return H
def from_dict(cls, dic):
""" Return an `AtomBasis` from a dictionary
Parameters
----------
dic : dict
"""
from sisl_toolbox.siesta.atom._atom import _shell_order
element = dic["element"]
tag = dic.get("tag")
mass = dic.get("mass", None)
# get default options for pseudo
opts = NotNonePropertyDict()
basis = dic.get("basis", {})
opts["ion_charge"] = parse_variable(basis.get("ion-charge")).value
opts["type"] = basis.get("type")
def get_radius(orbs, zeta):
for orb in orbs:
if orb.zeta == zeta:
return orb.R
raise ValueError("Could parse the negative R value")
orbs = []
for nl in dic:
if nl not in _shell_order:
continue
n, l = int(nl[0]), 'spdfg'.index(nl[1])
# Now we are sure we are dealing with valence shells
basis = dic[nl].get("basis", {})
opt_nl = NotNonePropertyDict()
orbs_nl = []
# Now read through the entries
for key, entry in basis.items():
if key in ("charge-confinement", "charge-conf"):
opt_nl["charge"] = [
parse_variable(entry.get("charge")).value,
parse_variable(entry.get("yukawa"),
unit='1/Ang').value,
parse_variable(entry.get("width"), unit='Ang').value
]
elif key in ("soft-confinement", "soft-conf"):
opt_nl["soft"] = [
parse_variable(entry.get("V0"), unit='eV').value,
parse_variable(entry.get("ri"), unit='Ang').value
]
elif key in ("filter", ):
opt_nl["filter"] = parse_variable(entry, unit='eV').value
elif key in ("split-norm", "split"):
opt_nl["split"] = parse_variable(entry).value
elif key in ("polarization", "pol"):
opt_nl["pol"] = parse_variable(entry).value
elif key.startswith("zeta"):
# cutoff of zeta
zeta = int(key[4:])
R = parse_variable(entry, unit='Ang').value
if R < 0:
R *= -get_radius(orbs_nl, zeta - 1)
orbs_nl.append(
si.AtomicOrbital(n=n, l=l, m=0, zeta=zeta, R=R))
if len(orbs_nl) > 0:
opts[(n, l)] = opt_nl
orbs.extend(orbs_nl)
atom = si.Atom(element, orbs, mass=mass, tag=tag)
return cls(atom, opts)
def from_block(cls, block):
""" Return an `Atom` for a specified basis block
Parameters
----------
block : list or str
the PAO.basis block (as read from an fdf file).
Should be a list of lines.
"""
if isinstance(block, str):
block = block.splitlines()
else:
# store local list
block = list(block)
def blockline():
nonlocal block
out = ""
while len(out) == 0:
out = block.pop(0).split('#')[0].strip()
return out
# define global opts
opts = {}
specie = blockline()
specie = specie.split()
if len(specie) == 4:
# we have Symbol, nl, type, ionic_charge
symbol, nl, opts["type"], opts["ion_charge"] = specie
elif len(specie) == 3:
# we have Symbol, nl, type
# or
# we have Symbol, nl, ionic_charge
symbol, nl, opt = specie
try:
opts["ion_charge"] = float(opt)
except:
opts["type"] = opt
elif len(specie) == 2:
# we have Symbol, nl
symbol, nl = specie
type = None
# now loop orbitals
orbs = []
for _ in range(int(nl)):
# we have 2 or 3 lines
nl_line = blockline()
rc_line = blockline()
# check if we have contraction in the line
# This is not perfect, but should grab
# contration lines rather than next orbital line.
# This is because the first n=<integer> should never
# contain a ".", whereas the contraction *should*.
if len(block) > 0:
if '.' in block[0].split()[0]:
contract_line = blockline()
# remove n=
nl_line = nl_line.replace("n=", "").split()
# first 3 are n, l, Nzeta
n = int(nl_line.pop(0))
l = int(nl_line.pop(0))
nzeta = int(nl_line.pop(0))
# assign defaults
nlopts = {}
while len(nl_line) > 0:
opt = nl_line.pop(0)
if opt == "P":
try:
npol = int(nl_line[0])
nl_line.pop(0)
nlopts["pol"] = npol
except:
nlopts["pol"] = 1
elif opt == "S":
nlopts["split"] = float(nl_line.pop(0))
elif opt == "F":
nlopts["filter"] = float(nl_line.pop(0)) / _eV2Ry
elif opt == "E":
# 1 or 2 values
V0 = float(nl_line.pop(0)) / _eV2Ry
try:
ri = float(nl_line[0]) / _Ang2Bohr
nl_line.pop(0)
except:
# default to None (uses siesta default)
ri = None
nlopts["soft"] = [V0, ri]
elif opt == "Q":
# 1, 2 or 3 values
charge = float(nl_line.pop(0))
try:
# this is in Bohr-1
yukawa = float(nl_line[0]) * _Ang2Bohr
nl_line.pop(0)
except:
# default to None (uses siesta default)
yukawa = None
try:
width = float(nl_line[0]) / _Ang2Bohr
nl_line.pop(0)
except:
# default to None (uses siesta default)
width = None
nlopts["charge"] = [charge, yukawa, width]
# now we have everything to build the orbitals etc.
for izeta, rc in enumerate(map(float, rc_line.split()), 1):
if rc > 0:
rc /= _Ang2Bohr
elif rc < 0 and izeta > 1:
rc *= -orbs[-1].R
elif rc == 0 and izeta > 1:
# this is ok, the split-norm will be used to
# calculate the radius
pass
else:
raise ValueError(
f"Could not parse the PAO.Basis block for the zeta ranges {rc_line}."
)
orb = si.AtomicOrbital(n=n, l=l, m=0, zeta=izeta, R=rc)
nzeta -= 1
orbs.append(orb)
# In case the final orbitals hasn't been defined.
# They really should be defined in this one, but sometimes it may be
# useful to leave the rc's definitions out.
rc = orbs[-1].R
for izeta in range(nzeta):
orb = si.AtomicOrbital(n=n,
l=l,
m=0,
zeta=orbs[-1].zeta + 1,
R=rc)
orbs.append(orb)
opts[(n, l)] = nlopts
# Now create the atom
atom = si.Atom(symbol, orbs)
return cls(atom, opts)
def from_input(cls, inp):
""" Return atom object respecting the input
Parameters
----------
inp : list or str
create `AtomInput` from the content of `inp`
"""
def _get_content(f):
if f.is_file():
return open(f, 'r').readlines()
return None
if isinstance(inp, (tuple, list)):
# it is already in correct format
pass
elif isinstance(inp, (str, Path)):
# convert to path
inp = Path(inp)
# Check if it is a path or an input
content = _get_content(inp)
if content is None:
content = _get_content(inp / "INP")
if content is None:
raise ValueError(
f"Could not find any input file in {str(inp)} or {str(inp / 'INP')}"
)
inp = content
else:
raise ValueError(f"Unknown input format inp={inp}?")
# Now read lines
defines = []
opts = PropertyDict()
def bypass_comments(inp):
if inp[0].startswith("#"):
inp.pop(0)
bypass_comments(inp)
def bypass(inp, defines):
bypass_comments(inp)
if inp[0].startswith("%define"):
line = inp.pop(0)
defines.append(line.split()[1].strip())
bypass(inp, defines)
bypass(inp, defines)
# Now prepare reading
# First line has to contain the *type* of calculation
# pg|pe|ae|pt <comment>
line = inp.pop(0).strip()
if line.startswith("pg"):
opts.cc = False
elif line.startswith("pe"):
opts.cc = True
# <flavor> logr?
line = inp.pop(0).strip().split()
opts.flavor = line[0]
if len(line) >= 2:
opts.logr = float(line[1]) / _Ang2Bohr
# <element> <xc>' rs'?
line = inp.pop(0)
symbol = line.split()[0]
# now get xc equation
if len(line) >= 11:
opts.equation = line[10:10]
opts.xc = line[:10].split()[1]
line = line.split()
if len(line) >= 3:
opts.libxc = int(line[2])
# currently not used line
inp.pop(0)
# core, valence
core, valence = inp.pop(0).split()
opts.core = int(core)
valence = int(valence)
orbs = []
for _ in range(valence):
n, l, *occ = inp.pop(0).split()
orb = PropertyDict()
orb.n = int(n)
orb.l = int(l)
# currently we don't distinguish between up/down
orb.q0 = sum(map(float, occ))
orbs.append(orb)
# now we read the line with rc's and core-correction
rcs = inp.pop(0).split()
if len(rcs) >= 6:
# core-correction
opts.rcore = float(rcs[5]) / _Ang2Bohr
for orb in orbs:
orb.R = float(rcs[orb.l]) / _Ang2Bohr
# Now create orbitals
orbs = [si.AtomicOrbital(**orb, m=0, zeta=1) for orb in orbs]
# now re-arrange ensuring we have correct order of l shells
orbs = sorted(orbs, key=lambda orb: orb.l)
atom = si.Atom(symbol, orbs)
return cls(atom, defines, **opts)
import plotly.graph_objs as go
import numpy as np
import sisl
r = np.linspace(0, 3.5, 50)
f = np.exp(-r)
orb = sisl.AtomicOrbital('2pzZ', (r, f))
geom = sisl.geom.graphene(orthogonal=True, atoms=sisl.Atom(6, orb))
geom = geom.move([0, 0, 5])
H = sisl.Hamiltonian(geom)
H.construct([(0.1, 1.44), (0, -2.7)], )
def test_eigenstate_wf():
plot = H.eigenstate()[0].plot.wavefunction(geometry=H.geometry)
assert len(plot.data) > 0
assert isinstance(plot.data[0], go.Isosurface)
def test_hamiltonian_wf():
# Check if it works for 3D plots
plot = H.plot.wavefunction(2)
assert isinstance(plot.data[0], go.Isosurface)
# Check that setting plot geom to True adds data traces
plot.update_settings(plot_geom=False)
def sp2(ext_geom,
t1=2.7,
t2=0.2,
t3=0.18,
eB=3.,
eN=-3.,
s0=1.0,
s1=0,
s2=0,
s3=0,
dq=0,
dim=2):
""" Function to create a Tight Binding Hamiltoninan for sp2 Carbon systems
It takes advantage of the `sisl` class for building sparse Hamiltonian matrices,
`sisl.physics.Hamiltonian`
It obtains the Hamiltonian for ``ext_geom`` (which must be a `sisl.Geometry` instance)
with the parameters for first, second and third nearest neighbors (``t1``, ``t2``, ``t3``).
One can also use a non-orthogonal basis of atomic orbitals by passing the parameters for the
overlap matrix between first, second and third nearest neighbors (``s1``, ``s2``, ``s3``).
The function will also take into account the possible presence of Boron or Nitrogen atoms,
for which one would need to specify the on-site energy for those atoms (``eB`` and ``eN``)
Returns
-------
H: sisl.physics.Hamiltonian
tight-binding Hamiltonian for the sp2 structure of ``dim=2`` (for the two spin channels)
"""
# Determine pz sites
aux = []
sp3 = []
for ia, atom in enumerate(ext_geom.atoms.iter()):
# Append non C-type atoms in aux list
if atom.Z not in [5, 6, 7]:
aux.append(ia)
idx = ext_geom.close(ia, R=[0.1, 1.6])
if len(idx[1]) == 4: # Search for atoms with 4 neighbors
if atom.Z == 6:
sp3.append(ia)
# Remove all sites not carbon-type
pi_geom = ext_geom.remove(aux + sp3)
pi_geom.reduce()
# Iterate over atomic species to set initial charge
maxR = 20
r = np.linspace(0, maxR, 700)
# In Slater-type orbitals (Hydrogen-like atom solution), the radial function is ~exp(-Zr/2a)
# where a=0.529 \AA is the Bohr radius and Z is the atomic number.
# We use the effective nuclear charge instead, which for Carbon atoms is approximately Zeff~3.
func = np.exp(-3 * r)
for atom, _ in pi_geom.atoms.iter(True):
pz = sisl.AtomicOrbital('pz', (r, func), R=maxR, q0=atom.Z - 5 + dq)
atom.orbitals[0] = pz
# Construct Hamiltonian
if s1 != 0:
orthogonal = False
else:
orthogonal = True
H = sisl.Hamiltonian(pi_geom, orthogonal=orthogonal, dim=dim)
# Radii defining 1st, 2nd, and 3rd neighbors
R = [0.1, 1.6, 2.6, 3.1]
# Build hamiltonian for backbone
for ia in pi_geom:
idx = pi_geom.close(ia, R=R)
# NB: I found that ':' is necessary in the following lines, but I don't understand why...
if pi_geom.atoms[ia].Z == 5:
H[ia, ia, :] = eB # set onsite for B sites
elif pi_geom.atoms[ia].Z == 7:
H[ia, ia, :] = eN # set onsite for N sites
# set hoppings
H[ia, idx[1], :] = -t1
if t2 != 0:
H[ia, idx[2], :] = -t2
if t3 != 0:
H[ia, idx[3], :] = -t3
if not H.orthogonal:
H.S[ia, ia] = s0
H.S[ia, idx[1]] = s1
H.S[ia, idx[2]] = s2
H.S[ia, idx[3]] = s3
return H
