ASE Manual Release 3.6.1.2825 CAMd - CampOS Wiki

ASE Manual, Release 3.6.1.2828
Parameters
label: str Prefix to use for filenames (label.txt, ...). Default is ‘dftb’.
write_dftb: boolean True: a minimal input file (name of which is always ‘dftb_in.hsd’) is written based on
values given here. False: input file for dftb+ is not written. User must have generated file ‘dftb_in.hsd’ in
the working directory. Use write_dftb=False to use your own ‘dftb_in.hsd’-file.
charge: float Total charge of the system.
include_dispersion: boolean True: Default dispersion parameters are written in the file ‘dftb_in.hsd’ (requires
that also write_dftb_input_file==True) False: dispersion parameters are not written here.
do_spin_polarized: boolean True: Spin polarized calculation False: Spin unpolarized calculation
unpaired_electrons: float Number of spin unpaired electrons in the system. Relevant only if
do_spin_polarized==True
fermi_temperature: float Fermi temperature for electrons.
scc: boolean True: Do charge self consistent dftb+ False: No SCC, charges on atoms are not iterated
Example1: Geometry Optimization
#!/usr/bin/env python
import os
from ase import Atoms
from ase.calculators.dftb import Dftb
from ase.optimize import QuasiNewton
from ase.io import write
d = 1.10
test = Atoms(’2O’, positions=[(0., 0., 0.), (0., 0., d)])
test.set_pbc([False, False, False])
test.set_calculator(Dftb(label=’o2’,write_dftb=True,do_spin_polarized=True,unpaired_electrons=2.0,
dyn = QuasiNewton(test, trajectory=’test.traj’)
dyn.run(fmax=0.01)
write(’test.final.xyz’, test)
Example2: Geometry Optimization using your own ‘dftb_in.hsd’ file
#!/usr/bin/python
from ase.io import read, write
from ase.calculators.dftb import Dftb
from ase.optimize import QuasiNewton
system = read(’h2o_1.xyz’)
system.set_calculator(Dftb(label=’dftb’,write_dftb=False))
qn = QuasiNewton(system)
qn.run(fmax=0.005)
write(’final.xyz’, system)
write(’final.traj’, system)
Input file for example 2 (h2o_1.xyz)
118 Chapter 7. Documentation for modules in ASE