convergence={'bands':60}, # It's better NOT to converge all bands.
eigensolver='cg', # It's preferable to use 'cg' to calculate unoccupied states.
occupations=FermiDirac(0.05),
txt='out_gs.txt')
atoms.set_calculator(calc)
atoms.get_potential_energy()
calc.write('graphite.gpw','all')
# Part 2: Spectra calculations
f = paropen('graphite_q_list', 'w') # Write down q.
for i in range(1,8): # Loop over different q.
df = DF(calc='graphite.gpw',
nbands=60, # Use only bands that are converged in the gs calculation.
q=np.array([i/20., 0., 0.]), # Gamma - M excitation
#q=np.array([i/20., -i/20., 0.]) # Gamma - K excitation
w=np.linspace(0, 40, 401), # Spectra from 0-40 eV with 0.1 eV spacing.
eta=0.2, # Broadening parameter.
ecut=40+(i-1)*10, # In general, larger q requires larger planewave cutoff energy. #
txt='out_df_%d.txt' %(i)) # Write differnt output for different q.
df1, df2 = df.get_dielectric_function()
df.get_EELS_spectrum(df1, df2, filename='graphite_EELS_%d' %(i)) # Use different filenames for different q
df.check_sum_rule(df1, df2) # Check f-sum rule.
print >> f, sqrt(np.inner(df.qq_v / Bohr, df.qq_v / Bohr))
w = np.linspace(0, 24, 481)
q = np.array([0.0, 0.00001, 0.])
# getting macroscopic constant
df = DF(calc='si.gpw', q=q, w=(0.,), eta=0.0001,
hilbert_trans=False, txt='df_1.out',
ecut=150, optical_limit=True)
df1, df2 = df.get_dielectric_function()
eM1, eM2 = df.get_macroscopic_dielectric_constant(df1, df2)
df.write('df_1.pckl')
if np.abs(eM1 - 13.992277) > 1e-4 or np.abs(eM2 - 12.589596) > 1e-4:
print eM1, eM2
raise ValueError('Pls check dielectric constant !')
#getting absorption spectrum
df = DF(calc='si.gpw', q=q, w=w, eta=0.1,
ecut=150, optical_limit=True, txt='df_2.out')
df1, df2 = df.get_dielectric_function()
df.get_absorption_spectrum(df1, df2, filename='si_abs')
df.check_sum_rule(df1, df2)
df.write('df_2.pckl')
if rank == 0 :
os.remove('si.gpw')
import numpy as np
from gpaw import GPAW
from gpaw.response.df import DF
w = np.linspace(0, 24., 481) # 0-24 eV with 0.05 eV spacing
q = np.array([0.0, 0.00001, 0.])
df = DF(calc='si.gpw',
q=q,
w=w,
eta=0.1, # Broadening parameter
ecut=150, # Energy cutoff for planewaves
optical_limit=True,
txt='df_2.out') # Output text
df1, df2 = df.get_dielectric_function()
df.get_absorption_spectrum(df1, df2, filename='si_abs.dat')
df.check_sum_rule(df1, df2)
df.write('df_2.pckl') # Save important parameters and data
hilbert_trans=False,
ecut=150,
optical_limit=True,
txt='df_1.out')
eM1, eM2 = df.get_macroscopic_dielectric_constant()
df.write('df_1.pckl')
if np.abs(eM1 - 13.991793) > 1e-3 or np.abs(eM2 - 12.589129) > 1e-3:
print eM1, eM2
raise ValueError('Please check dielectric constant !')
#getting absorption spectrum
df = DF(calc='si.gpw',
q=q,
w=w,
eta=0.1,
ecut=150,
optical_limit=True,
txt='df_2.out')
df.get_absorption_spectrum(filename='si_abs')
df.check_sum_rule()
df.write('df_2.pckl')
if rank == 0 :
os.remove('si.gpw')
eigensolver=
'cg', # It's preferable to use 'cg' to calculate unoccupied states.
occupations=FermiDirac(0.05),
txt='out_gs.txt')
atoms.set_calculator(calc)
atoms.get_potential_energy()
calc.write('graphite.gpw', 'all')
# Part 2: Spectra calculations
f = paropen('graphite_q_list', 'w') # Write down q.
for i in range(1, 8): # Loop over different q.
df = DF(
calc='graphite.gpw',
nbands=60, # Use only bands that are converged in the gs calculation.
q=np.array([i / 20., 0., 0.]), # Gamma - M excitation
#q=np.array([i/20., -i/20., 0.]) # Gamma - K excitation
w=np.linspace(0, 40, 401), # Spectra from 0-40 eV with 0.1 eV spacing.
eta=0.2, # Broadening parameter.
ecut=40 + (i - 1) *
10, # In general, larger q requires larger planewave cutoff energy. #
txt='out_df_%d.txt' % (i)) # Write differnt output for different q.
df1, df2 = df.get_dielectric_function()
df.get_EELS_spectrum(df1, df2, filename='graphite_EELS_%d' %
(i)) # Use different filenames for different q
df.check_sum_rule(df1, df2) # Check f-sum rule.
print >> f, sqrt(np.inner(df.qq_v / Bohr, df.qq_v / Bohr))
idiotproof=False, # allow uneven distribution of k-points
xc='LDA')
atoms.set_calculator(calc)
atoms.get_potential_energy()
#calc.write('Al.gpw','all')
t2 = time.time()
# Excited state calculation
q = np.array([1 / 4., 0., 0.])
w = np.linspace(0, 24, 241)
df = DF(calc=calc, q=q, w=w, eta=0.2, ecut=50)
df1, df2 = df.get_dielectric_function()
df.get_EELS_spectrum(df1, df2, filename='EELS_Al')
df.check_sum_rule()
t3 = time.time()
print 'For ground state calc, it took', (t2 - t1) / 60, 'minutes'
print 'For excited state calc, it took', (t3 - t2) / 60, 'minutes'
d = np.loadtxt('EELS_Al')
wpeak = 15.7 # eV
Nw = 157
if d[Nw, 1] > d[Nw - 1, 1] and d[Nw, 2] > d[Nw + 1, 2]:
pass
else:
raise ValueError('Plasmon peak not correct ! ')
if (np.abs(d[Nw, 1] - 28.8932274034) > 1e-5
nbands=70, # The result should also be converged with respect to bands.
convergence={'bands':60}, # It's better NOT to converge all bands.
eigensolver='cg', # It's preferable to use 'cg' to calculate unoccupied states.
occupations=FermiDirac(0.05),
txt='out_gs.txt')
atoms.set_calculator(calc)
atoms.get_potential_energy()
calc.write('graphite.gpw','all')
# Part 2: Spectra calculations
f = paropen('graphite_q_list', 'w') # Write down q.
for i in range(1,8): # Loop over different q.
df = DF(calc='graphite.gpw',
nbands=60, # Use only bands that are converged in the gs calculation.
q=np.array([i/20., 0., 0.]), # Gamma - M excitation
#q=np.array([i/20., -i/20., 0.]) # Gamma - K excitation
w=np.linspace(0, 40, 401), # Spectra from 0-40 eV with 0.1 eV spacing.
eta=0.2, # Broadening parameter.
ecut=40+(i-1)*10, # In general, larger q requires larger planewave cutoff energy. #
txt='out_df_%d.txt' %(i)) # Write differnt output for different q.
df.get_EELS_spectrum(filename='graphite_EELS_%d' %(i)) # Use different filenames for different q
df.check_sum_rule() # Check f-sum rule.
print >> f, sqrt(np.inner(df.qq_v / Bohr, df.qq_v / Bohr))
