atomicfile = 'atomic_energies.json'
generate_training_data(dbext)
with open(atomicfile, 'r') as f:
atomic_energies = json.load(f)
for mode in ['poly', 'exp_poly', 'exp_spline']:
rmins = {pair: 0.7 * 2 * rcov} if mode == 'exp_poly' else None
powers = {pair: range(2, 7) if 'poly' in mode else range(4)}
calc = TANGO([element],
DftCalc=None,
DftbPlusCalc=DftbPlusCalc,
mode=mode,
kptdensity=None,
maximum_angular_momenta=mam,
fit_constant='element',
kBT=2.0,
force_scaling=0.,
rcuts=rcuts,
rmins=rmins,
powers=powers)
residual = calc.fit_repulsion([dbfile],
run_checks=False,
atomic_energies=atomic_energies,
dimersdb=dimersdbfile)
suffix = '%s_%s' % (dbext, mode)
assert residual < 0.02, (suffix, residual)
os.system('mv %s.pdf %s_%s.pdf' % (pair, pair, suffix))
dbfiles = ['training.db']
force_scaling = 0.0 # how the forces should be weighted w.r.t. the forces;
# this does not matter here because the forces are zero by symmetry
rcov = covalent_radii[atomic_numbers['Si']]
rcuts = {
'Si-Si': 1.5 * 2 * rcov
} # 'outer' cutoff as approximately 1.5 times the NN distance
rmins = {
'Si-Si': 0.8 * 2 * rcov
} # 'inner' cutoff below which we switch to exponential repulsion
powers = {
'Si-Si': range(2, 7)
} # standard (rcut-r)**2 + ... + (rcut-r)**6 polynomial
calc = TANGO(
elements,
DftbPlusCalc=DftbPlusCalculator,
kptdensity=kptdensity,
rmins=rmins,
rcuts=rcuts,
powers=powers,
fit_constant=fit_constant,
kBT=kBT,
mode=mode,
force_scaling=force_scaling,
maximum_angular_momenta=mam,
)
residual = calc.fit_repulsion(dbfiles, run_checks=True)
print('Residual:', residual)
mam = {'C': 1, 'N': 1}
dbfile = 'training.json'
if os.path.exists(dbfile):
os.remove(dbfile)
generate_database(dbfile, rc)
for mode in ['poly', 'exp_poly', 'exp_spline']:
powers = {pair: range(2, 7) if 'poly' in mode else range(4)}
rmins = {pair: rmin} if 'exp' in mode else None
calc = TANGO(
elements,
DftCalc=None,
DftbPlusCalc=DftbPlusCalc,
mode=mode,
kptdensity=None,
maximum_angular_momenta=mam,
fit_constant=None,
kBT=2.,
force_scaling=1.,
rcuts=rcuts,
rmins=rmins,
powers=powers,
referencing=[range(18), [18, 19]],
)
residual = calc.fit_repulsion([dbfile], run_checks=False)
eps = 1e-6 if 'poly' in mode else 1e-2
assert residual < eps, (mode, residual, eps)
os.system('mv %s.pdf %s_%s.pdf' % (pair, pair, mode))