from ase import Atoms
from gpaw.tddft import photoabsorption_spectrum
from gpaw import PoissonSolver
from gpaw.lcaotddft.tddfpt import DensityCollector
from gpaw.lcaotddft import LCAOTDDFT
atoms = Atoms('Na8', positions=[[i * 3.0, 0, 0] for i in range(8)])
atoms.center(vacuum=5.0)
# Calculate all bands
td_calc = LCAOTDDFT(basis='dzp',
setups={'Na': '1'},
xc='LDA',
h=0.3,
nbands=4,
convergence={'density': 1e-7},
poissonsolver=PoissonSolver(eps=1e-14,
remove_moment=1 + 3 + 5))
atoms.set_calculator(td_calc)
atoms.get_potential_energy()
td_calc.write('Na8_gs.gpw', mode='all')
td_calc = LCAOTDDFT('Na8_gs.gpw')
td_calc.attach(DensityCollector('Na8.TdDen', td_calc))
td_calc.absorption_kick([1e-4, 0.0, 0.0])
td_calc.propagate(20, 1000, 'Na8.dm')
photoabsorption_spectrum('Na8.dm', 'Na8.spec', width=0.15)
from gpaw.lcaotddft import LCAOTDDFT
from gpaw.lcaotddft.dipolemomentwriter import DipoleMomentWriter
from gpaw.lcaotddft.wfwriter import WaveFunctionWriter
# Read the ground-state file
td_calc = LCAOTDDFT('gs.gpw', txt='td.out')
# Attach any data recording or analysis tools
DipoleMomentWriter(td_calc, 'dm.dat')
WaveFunctionWriter(td_calc, 'wf.ulm')
# Kick and propagate
td_calc.absorption_kick([1e-5, 0., 0.])
td_calc.propagate(20, 1500)
# Save the state for restarting later
td_calc.write('td.gpw', mode='all')
convergence = {'density': 1e-6}
# Increase accuracy of Poisson Solver and apply multipole corrections up to l=2
poissonsolver = PoissonSolver(eps=1e-14, remove_moment=1 + 3)
td_calc = LCAOTDDFT(xc='GLLBSC',
basis='GLLBSC.dz',
h=0.3,
nbands=352,
convergence=convergence,
poissonsolver=poissonsolver,
occupations=FermiDirac(0.1),
parallel={
'sl_default': (8, 8, 32),
'band': 2
})
atoms.set_calculator(td_calc)
# Relax the ground state
atoms.get_potential_energy()
# For demonstration purposes, save intermediate ground state result to a file
td_calc.write('ag55.gpw', mode='all')
td_calc = LCAOTDDFT('ag55.gpw', parallel={'sl_default': (8, 8, 32), 'band': 2})
td_calc.absorption_kick([1e-5, 0.0, 0.0])
td_calc.propagate(20, 500, 'ag55.dm')
photoabsorption_spectrum('ag55.dm', 'ag55.spec', width=0.2)