# coding: utf-8
# Copyright (c) Pymatgen Development Team.
# Distributed under the terms of the MIT License.
from __future__ import division, unicode_literals
import re
import math
import subprocess
import itertools
import logging
import numpy as np
from monty.fractions import lcm
import fractions
from six.moves import reduce
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
"""
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 multienum.x and
makestr.x available in the path. Please download the library at
http://enum.sourceforge.net/ 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)
"""
__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')
[docs]@requires(enum_cmd and which('makestr.x'),
"EnumlibAdaptor requires the executables 'enum.x' or 'multienum.x' "
"and 'makestr.x' to be in the path. Please download the library at"
"http://enum.sourceforge.net/ and follow the instructions in "
"the README to compile these two executables accordingly.")
class EnumlibAdaptor(object):
"""
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):
"""
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.
"""
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
def run(self):
"""
Run the enumeration.
"""
# Create a temporary directory for working.
with ScratchDir(".") as d:
logger.debug("Temp dir : {}".format(d))
try:
# 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 ValueError("Unable to enumerate structure.")
except Exception:
import sys
import traceback
exc_type, exc_value, exc_traceback = sys.exc_info()
traceback.print_exception(exc_type, exc_value, exc_traceback,
limit=10, file=sys.stdout)
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_and_occu.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()
curr_sites = list(itertools.chain.from_iterable(disordered_sites))
min_sgnum = get_sg_info(curr_sites)
logger.debug("Disorderd sites has sgnum %d" % (
min_sgnum))
# It could be that some of the ordered sites has a lower symmetry than
# the disordered sites. So we consider the lowest symmetry sites as
# disordered in our enumeration.
self.ordered_sites = []
to_add = []
if self.check_ordered_symmetry:
for sites in ordered_sites:
temp_sites = list(curr_sites) + sites
sgnum = get_sg_info(temp_sites)
if sgnum < min_sgnum:
logger.debug("Adding {} to sites to be ordered. "
"New sgnum {}"
.format(sites, sgnum))
to_add = sites
min_sgnum = sgnum
for sites in ordered_sites:
if sites == to_add:
index_species.append(sites[0].specie)
index_amounts.append(len(sites))
sp_label = len(index_species) - 1
logger.debug("Lowest symmetry {} sites are included in enum."
.format(sites[0].specie))
for site in sites:
coord_str.append("{} {}".format(
coord_format.format(*site.coords),
sp_label))
disordered_sites.append(sites)
else:
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("{}".format(len(index_species)))
output.append("{}".format(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("partial")
ndisordered = sum([len(s) for s in disordered_sites])
base = int(ndisordered*reduce(lcm,
[f.limit_denominator(
ndisordered *
self.max_cell_size).denominator
for f in map(fractions.Fraction,
index_amounts)]))
# 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)
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 = []
rs = subprocess.Popen(["makestr.x",
"struct_enum.out", str(0),
str(num_structs - 1)],
stdout=subprocess.PIPE,
stdin=subprocess.PIPE, close_fds=True)
rs.communicate()
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.
ordered_structure = Structure(
original_latt,
[site.species_and_occu for site in self.ordered_sites],
[site.frac_coords for site in self.ordered_sites])
inv_org_latt = np.linalg.inv(original_latt.matrix)
for n in range(1, num_structs + 1):
with open("vasp.{:06d}".format(n)) 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_and_occu,
site.frac_coords,
super_latt).to_unit_cell)
structs.append(Structure.from_sites(sorted(sites)))
logger.debug("Read in a total of {} structures.".format(num_structs))
return structs