pwtools.calculators.Pwscf

class pwtools.calculators.Pwscf(**kwds)

Bases: FileIOCalculator, CalculatorBase

Pwscf (pw.x) calculator.

ATM, we don’t write a ase.calculators.calculator.Parameters class (dict) and have no read() method so I guess that restarts don’t work. Only simple SCF runs for now.

Examples

Define a calculator object:

>>> calc=Pwscf(label='pw',
...            directory='/path/to/calculation/dir',
...            kpts=1/0.35,
...            ecutwfc=80,
...            conv_thr=1e-8,
...            pp='pbe-n-kjpaw_psl.0.1.UPF',
...            pseudo_dir='/home/schmerler/soft/share/espresso/pseudo/espresso/',
...            calc_name='my_calc',
...            outdir='/scratch/schmerler/',
...            command='mpirun -np 16 pw.x < pw.in > pw.out')
>>> at=crys.Structure(...).get_ase_atoms(pbc=True)
>>> at.set_calculator(calc)
>>> at.get_potential_energy()

Relation to ASE k-grid tools:

>>> import numpy as np
>>> from ase.calculators.calculator import kpts2mp
>>> from pwtools.crys import kgrid
>>> st=crys.Structure(cell=np.diag([5,3,3]),
...                   coords=rand(5,3),
...                   symbols=['H']*5)
>>> at=st.get_ase_atoms(pbc=True)
>>> crys.kgrid(st.cell, h=0.35)
array([4, 6, 6])
>>> kpts2mp(at, kpts=1/0.35)
array([4, 6, 6])

__init__(**kwds)

Parameters:

• parameters (All) –

• label (str) – Basename of input and output files (e.g. ‘pw’). ASE’s FileIOCalculator will then set: self.prefix=label, while self.label will become {self.directory}/{self.prefix}. Don’t ask :) In self.command, we use ‘{self.prefix}.in’ and ‘{self.prefix}.out’ as file names.

• directory (str) – Path to a calculation dir where input and output files shall be written, e.g. pw.in and pw.out.

• kpts (ASE k-points description) – Examples: 3.5, [6,6,4]. If a float x is used, then it is the inverse of the k-grid spacing h per reciprocal axis as in kpts=pwtools.crys.kgrid(struct.cell, h=1/x)

• calc_name (str) – ‘prefix’ in PWscf input files

• pp (str or sequence) – Definition of the pseudopotential file and thus xc. If pp is a string (e.g. ‘pbe-n-kjpaw_psl.0.1.UPF’), then the atom symbols are used to build the PP file name '<atom_symbol>.pbe-n-kjpaw_psl.0.1.UPF' for each atom type. Needs a file of that name in pseudo_dir. If pp is a list, e.g. ['Al.pbe-n-kjpaw_psl.0.1.UPF', 'N.pbe-n-kjpaw_psl.0.1.UPF'], then this is used for each atom type.

• outdir – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• pseudo_dir – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• ecutwfc – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• ecutrho – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• diagonalization – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• mixing_mode – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• mixing_beta – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• electron_maxstep – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• conv_thr – as in PWscf, see http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html

• backup (bool) – make backup of old pw.in and pw.out if found, uses backup()

Methods

fill_infile_templ()	Replace all placeholders in self.infile_templ.
init_params_from_input(kwds)	Set self.parameters = self.default_parameters and update with input keyword arguments kwds.
read_results()
write_input(atoms[, properties, system_changes])

Attributes

default_parameters
implemented_properties
infile_templ