Source code for MDAnalysis.coordinates.FHIAIMS
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"""
FHI-AIMS file format --- :mod:`MDAnalysis.coordinates.FHIAIMS`
==============================================================
Classes to read and write `FHI-AIMS`_ coordinate files.
The cell vectors are specified by the (optional) lines with the
``lattice_vector`` tag::
lattice_vector x y z
where x, y, and z are expressed in ångström (Å).
.. Note::
In the original `FHI-AIMS format`_, up to three lines with
``lattice_vector`` are allowed (order matters) where the absent line implies
no periodicity in that direction. In MDAnalysis, only the case of no
``lattice_vector`` or three ``lattice_vector`` lines are allowed.
Atomic positions and names are specified either by the ``atom`` or by the
``atom_frac`` tags::
atom x y z name
atom_frac nx ny nz name
where x, y, and z are expressed in ångström, and nx, ny and nz are real numbers
in [0, 1] and are used to compute the atomic positions in units of the basic
cell.
Atomic velocities can be added on the line right after the corresponding
``atom`` in units of Å/ps using the ``velocity`` tag::
velocity vx vy vz
The field name is a string identifying the atomic species. See also the
specifications in the official `FHI-AIMS format`_.
Classes
-------
.. autoclass:: FHIAIMSReader
:members:
:inherited-members:
.. autoclass:: FHIAIMSWriter
:members:
:inherited-members:
Developer notes: ``FHIAIMSWriter`` format strings
-------------------------------------------------
The :class:`FHIAIMSWriter` class has a :attr:`FHIAIMSWriter.fmt`
attribute, which is a dictionary of different strings for writing
lines in ``.in`` files. These are as follows:
``xyz``
An atom line without velocities. Requires that the `name` and
`pos` keys be supplied. E.g.::
fmt['xyz'].format(pos=(0.0, 1.0, 2.0), name='O')
``vel``
An line that specifies velocities::
fmt['xyz'].format(vel=(0.1, 0.2, 0.3))
``box_triclinic``
The (optional) initial lines of the file which gives box dimensions.
Requires the `box` keyword, as a length 9 vector. This is a flattened
version of the (3, 3) triclinic vector representation of the unit
cell.
.. Links
.. _FHI-AIMS: https://aimsclub.fhi-berlin.mpg.de/
.. _FHI-AIMS format: https://doi.org/10.6084/m9.figshare.12413477.v1
"""
import re
import itertools
import warnings
import numpy as np
from . import base
from .core import triclinic_box, triclinic_vectors
from ..exceptions import NoDataError
from ..lib import util
from ..lib import mdamath
[docs]
class FHIAIMSReader(base.SingleFrameReaderBase):
"""Reader for the FHIAIMS geometry format.
Single frame reader for the `FHI-AIMS`_ input file format. Reads
geometry (3D and molecules only), positions (absolut or fractional),
velocities if given, all according to the `FHI-AIMS format`_
specifications
"""
format = ['IN', 'FHIAIMS']
units = {'time': 'ps', 'length': 'Angstrom', 'velocity': 'Angstrom/ps'}
def _read_first_frame(self):
with util.openany(self.filename, 'rt') as fhiaimsfile:
relative, positions, velocities, lattice_vectors = [], [], [], []
skip_tags = ["#", "initial_moment"]
oldline = ''
for line in fhiaimsfile:
line = line.strip()
if line.startswith("atom"):
positions.append(line.split()[1:-1])
relative.append('atom_frac' in line)
oldline = line
continue
if line.startswith("velocity"):
if not 'atom' in oldline:
raise ValueError(
'Non-conforming line (velocity must follow atom): ({0})in FHI-AIMS input file {0}'.format(line, self.filename))
velocities.append(line.split()[1:])
oldline = line
continue
if line.startswith("lattice"):
lattice_vectors.append(line.split()[1:])
oldline = line
continue
if any([line.startswith(tag) for tag in skip_tags]):
oldline = line
continue
raise ValueError(
'Non-conforming line: ({0})in FHI-AIMS input file {0}'.format(line, self.filename))
# positions and velocities are lists of lists of strings; they will be
# cast to np.arrays(..., dtype=float32) during assignment to ts.positions/ts.velocities
lattice_vectors = np.asarray(lattice_vectors, dtype=np.float32)
if len(velocities) not in (0, len(positions)):
raise ValueError(
'Found incorrect number of velocity tags ({0}) in the FHI-AIMS file, should be {1}.'.format(
len(velocities), len(positions)))
if len(lattice_vectors) not in (0, 3):
raise ValueError(
'Found partial periodicity in FHI-AIMS file. This cannot be handled by MDAnalysis.')
if len(lattice_vectors) == 0 and any(relative):
raise ValueError(
'Found relative coordinates in FHI-AIMS file without lattice info.')
# create Timestep
self.n_atoms = n_atoms = len(positions)
self.ts = ts = self._Timestep(n_atoms, **self._ts_kwargs)
ts.positions = positions
if len(lattice_vectors) > 0:
ts.dimensions = triclinic_box(*lattice_vectors)
ts.positions[relative] = np.matmul(ts.positions[relative], lattice_vectors)
if len(velocities) > 0:
ts.velocities = velocities
self.ts.frame = 0 # 0-based frame number
[docs]
def Writer(self, filename, n_atoms=None, **kwargs):
"""Returns a FHIAIMSWriter for *filename*.
Parameters
----------
filename: str
filename of the output FHI-AIMS file
Returns
-------
:class:`FHIAIMSWriter`
"""
if n_atoms is None:
n_atoms = self.n_atoms
return FHIAIMSWriter(filename, n_atoms=n_atoms, **kwargs)
[docs]
class FHIAIMSWriter(base.WriterBase):
"""FHI-AIMS Writer.
Single frame writer for the `FHI-AIMS`_ format. Writes geometry (3D and
molecules only), positions (absolut only), velocities if given, all
according to the `FHI-AIMS format`_ specifications.
If no atom names are given, it will set each atom name to "X".
"""
format = ['IN', 'FHIAIMS']
units = {'time': None, 'length': 'Angstrom', 'velocity': 'Angstrom/ps'}
#: format strings for the FHI-AIMS file (all include newline)
fmt = {
# coordinates output format, see https://doi.org/10.6084/m9.figshare.12413477.v1
'xyz': "atom {pos[0]:12.8f} {pos[1]:12.8f} {pos[2]:12.8f} {name:<3s}\n",
'vel': "velocity {vel[0]:12.8f} {vel[1]:12.8f} {vel[2]:12.8f}\n",
# unitcell
'box_triclinic': "lattice_vector {box[0]:12.8f} {box[1]:12.8f} {box[2]:12.8f}\nlattice_vector {box[3]:12.8f} {box[4]:12.8f} {box[5]:12.8f}\nlattice_vector {box[6]:12.8f} {box[7]:12.8f} {box[8]:12.8f}\n"
}
def __init__(self, filename, convert_units=True, n_atoms=None, **kwargs):
"""Set up the FHI-AIMS Writer
Parameters
-----------
filename : str
output filename
n_atoms : int (optional)
number of atoms
"""
self.filename = util.filename(filename, ext='.in', keep=True)
self.n_atoms = n_atoms
def _write_next_frame(self, obj):
"""Write selection at current trajectory frame to file.
Parameters
-----------
obj : AtomGroup or Universe
.. versionchanged:: 2.0.0
Support for deprecated Timestep argument has now been removed.
Use AtomGroup or Universe as an input instead.
"""
# write() method that complies with the Trajectory API
try:
# make sure to use atoms (Issue 46)
ag = obj.atoms
# can write from selection == Universe (Issue 49)
except AttributeError:
errmsg = "Input obj is neither an AtomGroup or Universe"
raise TypeError(errmsg) from None
# Check for topology information
missing_topology = []
try:
names = ag.names
except (AttributeError, NoDataError):
names = itertools.cycle(('X',))
missing_topology.append('names')
try:
atom_indices = ag.ids
except (AttributeError, NoDataError):
atom_indices = range(1, ag.n_atoms+1)
missing_topology.append('ids')
if missing_topology:
warnings.warn(
"Supplied AtomGroup was missing the following attributes: "
"{miss}. These will be written with default values. "
"".format(miss=', '.join(missing_topology)))
positions = ag.positions
try:
velocities = ag.velocities
has_velocities = True
except (AttributeError, NoDataError):
has_velocities = False
with util.openany(self.filename, 'wt') as output_fhiaims:
# Lattice
try: # for AtomGroup/Universe
tri_dims = obj.universe.trajectory.ts.triclinic_dimensions
except AttributeError: # for Timestep
tri_dims = obj.triclinic_dimensions
# full output
if tri_dims is not None:
output_fhiaims.write(
self.fmt['box_triclinic'].format(box=tri_dims.flatten()))
# Atom descriptions and coords
# Dont use enumerate here,
# all attributes could be infinite cycles!
for atom_index, name in zip(
range(ag.n_atoms), names):
output_fhiaims.write(self.fmt['xyz'].format(
pos=positions[atom_index],
name=name))
if has_velocities:
output_fhiaims.write(self.fmt['vel'].format(
vel=velocities[atom_index]))