# coding: utf-8
# Copyright (c) Pymatgen Development Team.
# Distributed under the terms of the MIT License.
"""
This module implements an interface to enumlib, Gus Hart"s excellent Fortran
code for enumerating derivative structures.
This module depends on a compiled enumlib with the executables enum.x and
makestr.x available in the path. Please download the library at
https://github.com/msg-byu/enumlib and follow the instructions in the README to
compile these two executables accordingly.
If you use this module, please cite the following:
Gus L. W. Hart and Rodney W. Forcade, "Algorithm for generating derivative
structures," Phys. Rev. B 77 224115 (26 June 2008)
Gus L. W. Hart and Rodney W. Forcade, "Generating derivative structures from
multilattices: Application to hcp alloys," Phys. Rev. B 80 014120 (July 2009)
Gus L. W. Hart, Lance J. Nelson, and Rodney W. Forcade, "Generating
derivative structures at a fixed concentration," Comp. Mat. Sci. 59
101-107 (March 2012)
Wiley S. Morgan, Gus L. W. Hart, Rodney W. Forcade, "Generating derivative
superstructures for systems with high configurational freedom," Comp. Mat.
Sci. 136 144-149 (May 2017)
"""
import re
import math
import subprocess
import itertools
import logging
import glob
import numpy as np
from monty.fractions import lcm
import fractions
from pymatgen.io.vasp.inputs import Poscar
from pymatgen.core.sites import PeriodicSite
from pymatgen.core.structure import Structure
from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
from pymatgen.core.periodic_table import DummySpecie
from monty.os.path import which
from monty.dev import requires
from monty.tempfile import ScratchDir
from threading import Timer
__author__ = "Shyue Ping Ong"
__copyright__ = "Copyright 2012, The Materials Project"
__version__ = "0.1"
__maintainer__ = "Shyue Ping Ong"
__email__ = "shyuep@gmail.com"
__date__ = "Jul 16, 2012"
logger = logging.getLogger(__name__)
# Favor the use of the newer "enum.x" by Gus Hart instead of the older
# "multienum.x"
enum_cmd = which('enum.x') or which('multienum.x')
# prefer makestr.x at present
makestr_cmd = which('makestr.x') or which('makeStr.x') or which('makeStr.py')
@requires(enum_cmd and makestr_cmd,
"EnumlibAdaptor requires the executables 'enum.x' or 'multienum.x' "
"and 'makestr.x' or 'makeStr.py' to be in the path. Please download the "
"library at https://github.com/msg-byu/enumlib and follow the instructions "
"in the README to compile these two executables accordingly.")
class EnumlibAdaptor:
"""
An adaptor for enumlib.
.. attribute:: structures
List of all enumerated structures.
"""
amount_tol = 1e-5
def __init__(self, structure, min_cell_size=1, max_cell_size=1,
symm_prec=0.1, enum_precision_parameter=0.001,
refine_structure=False, check_ordered_symmetry=True,
timeout=None):
"""
Initializes the adapter with a structure and some parameters.
Args:
structure: An input structure.
min_cell_size (int): The minimum cell size wanted. Defaults to 1.
max_cell_size (int): The maximum cell size wanted. Defaults to 1.
symm_prec (float): Symmetry precision. Defaults to 0.1.
enum_precision_parameter (float): Finite precision parameter for
enumlib. Default of 0.001 is usually ok, but you might need to
tweak it for certain cells.
refine_structure (bool): If you are starting from a structure that
has been relaxed via some electronic structure code,
it is usually much better to start with symmetry determination
and then obtain a refined structure. The refined structure have
cell parameters and atomic positions shifted to the expected
symmetry positions, which makes it much less sensitive precision
issues in enumlib. If you are already starting from an
experimental cif, refinement should have already been done and
it is not necessary. Defaults to False.
check_ordered_symmetry (bool): Whether to check the symmetry of
the ordered sites. If the symmetry of the ordered sites is
lower, the lowest symmetry ordered sites is included in the
enumeration. This is important if the ordered sites break
symmetry in a way that is important getting possible
structures. But sometimes including ordered sites
slows down enumeration to the point that it cannot be
completed. Switch to False in those cases. Defaults to True.
timeout (float): If specified, will kill enumlib after specified
time in minutes. This can be useful for gracefully handling
enumerations in a high-throughput context, for some enumerations
which will not terminate in a realistic length of time.
"""
if refine_structure:
finder = SpacegroupAnalyzer(structure, symm_prec)
self.structure = finder.get_refined_structure()
else:
self.structure = structure
self.min_cell_size = min_cell_size
self.max_cell_size = max_cell_size
self.symm_prec = symm_prec
self.enum_precision_parameter = enum_precision_parameter
self.check_ordered_symmetry = check_ordered_symmetry
self.structures = None
self.timeout = timeout
def run(self):
"""
Run the enumeration.
"""
# Create a temporary directory for working.
with ScratchDir(".") as d:
logger.debug("Temp dir : {}".format(d))
# Generate input files
self._gen_input_file()
# Perform the actual enumeration
num_structs = self._run_multienum()
# Read in the enumeration output as structures.
if num_structs > 0:
self.structures = self._get_structures(num_structs)
else:
raise EnumError("Unable to enumerate structure.")
def _gen_input_file(self):
"""
Generate the necessary struct_enum.in file for enumlib. See enumlib
documentation for details.
"""
coord_format = "{:.6f} {:.6f} {:.6f}"
# Using symmetry finder, get the symmetrically distinct sites.
fitter = SpacegroupAnalyzer(self.structure, self.symm_prec)
symmetrized_structure = fitter.get_symmetrized_structure()
logger.debug("Spacegroup {} ({}) with {} distinct sites".format(
fitter.get_space_group_symbol(),
fitter.get_space_group_number(),
len(symmetrized_structure.equivalent_sites))
)
"""
Enumlib doesn"t work when the number of species get too large. To
simplify matters, we generate the input file only with disordered sites
and exclude the ordered sites from the enumeration. The fact that
different disordered sites with the exact same species may belong to
different equivalent sites is dealt with by having determined the
spacegroup earlier and labelling the species differently.
"""
# index_species and index_amounts store mappings between the indices
# used in the enum input file, and the actual species and amounts.
index_species = []
index_amounts = []
# Stores the ordered sites, which are not enumerated.
ordered_sites = []
disordered_sites = []
coord_str = []
for sites in symmetrized_structure.equivalent_sites:
if sites[0].is_ordered:
ordered_sites.append(sites)
else:
sp_label = []
species = {k: v for k, v in sites[0].species.items()}
if sum(species.values()) < 1 - EnumlibAdaptor.amount_tol:
# Let us first make add a dummy element for every single
# site whose total occupancies don't sum to 1.
species[DummySpecie("X")] = 1 - sum(species.values())
for sp in species.keys():
if sp not in index_species:
index_species.append(sp)
sp_label.append(len(index_species) - 1)
index_amounts.append(species[sp] * len(sites))
else:
ind = index_species.index(sp)
sp_label.append(ind)
index_amounts[ind] += species[sp] * len(sites)
sp_label = "/".join(["{}".format(i) for i in sorted(sp_label)])
for site in sites:
coord_str.append("{} {}".format(
coord_format.format(*site.coords),
sp_label))
disordered_sites.append(sites)
def get_sg_info(ss):
finder = SpacegroupAnalyzer(Structure.from_sites(ss),
self.symm_prec)
return finder.get_space_group_number()
target_sgnum = get_sg_info(symmetrized_structure.sites)
curr_sites = list(itertools.chain.from_iterable(disordered_sites))
sgnum = get_sg_info(curr_sites)
ordered_sites = sorted(ordered_sites, key=lambda sites: len(sites))
logger.debug("Disordered sites has sg # %d" % (sgnum))
self.ordered_sites = []
# progressively add ordered sites to our disordered sites
# until we match the symmetry of our input structure
if self.check_ordered_symmetry:
while sgnum != target_sgnum and len(ordered_sites) > 0:
sites = ordered_sites.pop(0)
temp_sites = list(curr_sites) + sites
new_sgnum = get_sg_info(temp_sites)
if sgnum != new_sgnum:
logger.debug("Adding %s in enum. New sg # %d"
% (sites[0].specie, new_sgnum))
index_species.append(sites[0].specie)
index_amounts.append(len(sites))
sp_label = len(index_species) - 1
for site in sites:
coord_str.append("{} {}".format(
coord_format.format(*site.coords),
sp_label))
disordered_sites.append(sites)
curr_sites = temp_sites
sgnum = new_sgnum
else:
self.ordered_sites.extend(sites)
for sites in ordered_sites:
self.ordered_sites.extend(sites)
self.index_species = index_species
lattice = self.structure.lattice
output = [self.structure.formula, "bulk"]
for vec in lattice.matrix:
output.append(coord_format.format(*vec))
output.append("%d" % len(index_species))
output.append("%d" % len(coord_str))
output.extend(coord_str)
output.append("{} {}".format(self.min_cell_size, self.max_cell_size))
output.append(str(self.enum_precision_parameter))
output.append("full")
ndisordered = sum([len(s) for s in disordered_sites])
base = int(ndisordered*lcm(*[f.limit_denominator(ndisordered * self.max_cell_size).denominator
for f in map(fractions.Fraction, index_amounts)]))
# This multiplicative factor of 10 is to prevent having too small bases
# which can lead to rounding issues in the next step.
# An old bug was that a base was set to 8, with a conc of 0.4:0.6. That
# resulted in a range that overlaps and a conc of 0.5 satisfying this
# enumeration. See Cu7Te5.cif test file.
base *= 10
# base = ndisordered #10 ** int(math.ceil(math.log10(ndisordered)))
# To get a reasonable number of structures, we fix concentrations to the
# range expected in the original structure.
total_amounts = sum(index_amounts)
for amt in index_amounts:
conc = amt / total_amounts
if abs(conc * base - round(conc * base)) < 1e-5:
output.append("{} {} {}".format(int(round(conc * base)),
int(round(conc * base)),
base))
else:
min_conc = int(math.floor(conc * base))
output.append("{} {} {}".format(min_conc - 1, min_conc + 1,
base))
output.append("")
logger.debug("Generated input file:\n{}".format("\n".join(output)))
with open("struct_enum.in", "w") as f:
f.write("\n".join(output))
def _run_multienum(self):
p = subprocess.Popen([enum_cmd],
stdout=subprocess.PIPE,
stdin=subprocess.PIPE, close_fds=True)
if self.timeout:
timed_out = False
timer = Timer(self.timeout*60, lambda p: p.kill(), [p])
try:
timer.start()
output = p.communicate()[0].decode("utf-8")
finally:
if not timer.is_alive():
timed_out = True
timer.cancel()
if timed_out:
raise TimeoutError('Enumeration took too long.')
else:
output = p.communicate()[0].decode("utf-8")
count = 0
start_count = False
for line in output.strip().split("\n"):
if line.strip().endswith("RunTot"):
start_count = True
elif start_count and re.match(r"\d+\s+.*", line.strip()):
count = int(line.split()[-1])
logger.debug("Enumeration resulted in {} structures".format(count))
return count
def _get_structures(self, num_structs):
structs = []
if ".py" in makestr_cmd:
options = ["-input", "struct_enum.out", str(1), str(num_structs)]
else:
options = ["struct_enum.out", str(0), str(num_structs - 1)]
rs = subprocess.Popen([makestr_cmd] + options,
stdout=subprocess.PIPE,
stdin=subprocess.PIPE, close_fds=True)
stdout, stderr = rs.communicate()
if stderr:
logger.warning(stderr.decode())
# sites retrieved from enumlib will lack site properties
# to ensure consistency, we keep track of what site properties
# are missing and set them to None
# TODO: improve this by mapping ordered structure to original
# disorded structure, and retrieving correct site properties
disordered_site_properties = {}
if len(self.ordered_sites) > 0:
original_latt = self.ordered_sites[0].lattice
# Need to strip sites of site_properties, which would otherwise
# result in an index error. Hence Structure is reconstructed in
# the next step.
site_properties = {}
for site in self.ordered_sites:
for k, v in site.properties.items():
disordered_site_properties[k] = None
if k in site_properties:
site_properties[k].append(v)
else:
site_properties[k] = [v]
ordered_structure = Structure(
original_latt,
[site.species for site in self.ordered_sites],
[site.frac_coords for site in self.ordered_sites],
site_properties=site_properties
)
inv_org_latt = np.linalg.inv(original_latt.matrix)
for file in glob.glob('vasp.*'):
with open(file) as f:
data = f.read()
data = re.sub(r'scale factor', "1", data)
data = re.sub(r'(\d+)-(\d+)', r'\1 -\2', data)
poscar = Poscar.from_string(data, self.index_species)
sub_structure = poscar.structure
# Enumeration may have resulted in a super lattice. We need to
# find the mapping from the new lattice to the old lattice, and
# perform supercell construction if necessary.
new_latt = sub_structure.lattice
sites = []
if len(self.ordered_sites) > 0:
transformation = np.dot(new_latt.matrix, inv_org_latt)
transformation = [[int(round(cell)) for cell in row]
for row in transformation]
logger.debug("Supercell matrix: {}".format(transformation))
s = ordered_structure * transformation
sites.extend([site.to_unit_cell() for site in s])
super_latt = sites[-1].lattice
else:
super_latt = new_latt
for site in sub_structure:
if site.specie.symbol != "X": # We exclude vacancies.
sites.append(
PeriodicSite(site.species,
site.frac_coords,
super_latt,
to_unit_cell=True,
properties=disordered_site_properties)
)
else:
logger.debug("Skipping sites that include species X.")
structs.append(Structure.from_sites(sorted(sites)))
logger.debug("Read in a total of {} structures.".format(num_structs))
return structs
[docs]class EnumError(BaseException):
"""
Error subclass for enumeration errors.
"""
pass