New spinw syntax proposal

pyspinw_syntax_proposal.py

from ase import Atom
from spinw import Lattice, Interaction
import numpy as np
import matplotlib.pyplot as plt

"""
% Matlab code
linipo = spinw;
linipo.genlattice('lat_const', [10.02 5.86 4.68],'sym','P n m a');
linipo.addatom('r',[1/4 1/4 0],'S',1,'label','MNi2','color','b')
linipo.genmagstr('mode','direct','S',[0 0 0 0; 0 0 0 0; 1 -1 -1 1])
"""

#mn = Atom('Mn', position=[1/4, 1/4, 0], magmom=1)
#spins = Lattice(lat_const=[10.02, 5.86, 4.68], sym='P n m a', atoms=[mn])
#spins.genmagstr(mode='direct', basis=[[0,0,1], [0,0,-1], [0,0,-1], [0,0,1]])

#mn1 = Atom('Mn', position=[1/4, 1/4, 0], magmom=[0,0,1])
#mn2 = Atom('Mn', position=[3/4, 1/4, 1/2], magmom=[0,0,-1])
#mn3 = Atom('Mn', position=[1/4, 3/4, 1/2], magmom=[0,0,-1])
#mn4 = Atom('Mn', position=[1/4, 3/4, 0], magmom=[0,0,1])
#spins = Lattice(lat_const=[10.02, 5.86, 4.68], atoms=[mn1, mn2, mn3, mn4])
#magnetic_structure = MagStruct(basis=[mn1, mn2, mn3, mn4], propagation_vector=[0,0,0])

mn = Atom('Mn', position=[1/4, 1/4, 0], magmom=1, anisotropy=np.diag([0.1969, 0.9097, 0]))
atoms = GenerateFromSymmetry(lat_const=[10.02, 5.84, 4.68], sym='P n m a', unique_atoms=[mn])
# atoms = [Atom('Mn', position=[0.25, 0.25, 0]), Atom('Mn', position=[0.75, 0.25, 0]) ...]
atoms[0].magmom = [0,0,-1]
k1 = Component(atoms, propagation_vector=[0,0,0])
k2 = Component(atoms, propagation_vector=[0,0,0.5], magmom=[[...]])
magstruct = MagneticStructure([k1, k2])
#magnetic_structure = MagStruct(atoms, propagation_vector=[[0,0,0],[0,0,0.5]])
#atoms = GenerateFromSymmetry(lat_const=[10.02, 5.84, 4.68], sym='P n m a', unique_atoms=[mn],
#                             irrep='GM') # Look up in Bilbao Crystallographic Server - maybe?

"""
linipo.gencoupling()
linipo.addmatrix('label','Jbc','value',  1.036);  linipo.addcoupling('mat','Jbc','bond',1)
linipo.addmatrix('label','Jb', 'value',  0.6701); linipo.addcoupling('mat','Jc' ,'bond',2)
linipo.addmatrix('label','Jc', 'value', -0.0469); linipo.addcoupling('mat','Jb' ,'bond',7)
linipo.addmatrix('label','Jab','value',  0.2977); linipo.addcoupling('mat','Jab','bond',[5 6])
linipo.addmatrix('label','Jac','value', -0.1121); linipo.addcoupling('mat','Jac','bond',[3 4])
linipo.addmatrix('label','D',  'value', np.diag([0.1969, 0.9097, 0]))
linipo.addaniso('D')
"""

Jbc = Interaction(label='Jbc', value=1.036, bond_index=0)
Jb  = Interaction(label='Jb', value=0.6701, bond_index=1)
Jc  = Interaction(label='Jc', value=-0.0469, bond_index=6)
Jab = Interaction(label='Jab', value=0.2977, bond_index=[4, 5])
Jac = Interaction(label='Jac', value=-0.1121, bond_index=[2, 3])

Aa = AtomTerm(anisotopty = aaa, g=2.1??)
Ab = AtomTerm(anisotopty = aaa, g=default None)
Ab ...

mymodel = SpinModel(structure=magstruct, interactions=[Jbc, Jb, Jc, Jab, Jac], g=None)

"""
linipoSpec = linipo.spinwave({[0 1 0] [2 1 0]});
linipoSpec = sw_egrid(linipoSpec);
linipoSpec = sw_omegasum(linipoSpec,'zeroint',1e-3);
figure
subplot(3,1,1)
sw_plotspec(linipoSpec,'mode','disp','axLim',[0 8],'colormap',[0 0 0],'colorbar',false)
subplot(3,1,2)
sw_plotspec(linipoSpec,'mode','int','axLim',[0 15],'colormap',[0 0 0],'colorbar',false)
subplot(3,1,3)
sw_plotspec(linipoSpec,'mode','color')
"""

spec = spins.spinwave(([0,1,0], [2,1,0]))
spec.egrid().omegasum(zeroint=1e-3)
fig, ax = plt.subplots(3, 1, subplot_kw={'projection':'spinw'})
ax[0].plot(spec)
ax[0].set_ylim([0, 8])
ax[1].plot(spec.intensity())
ax[1].set_ylim([0, 15])
ax[2].pcolormesh(spec)