Source code for pymatgen.entries.exp_entries

# coding: utf-8
# Copyright (c) Pymatgen Development Team.
# Distributed under the terms of the MIT License.

from __future__ import division, unicode_literals

"""
This module defines Entry classes for containing experimental data.
"""


__author__ = "Shyue Ping Ong"
__copyright__ = "Copyright 2012, The Materials Project"
__version__ = "0.1"
__maintainer__ = "Shyue Ping Ong"
__email__ = "shyuep@gmail.com"
__date__ = "Jun 27, 2012"


from pymatgen.analysis.phase_diagram import PDEntry
from pymatgen.core.composition import Composition
from monty.json import MSONable
from pymatgen.analysis.thermochemistry import ThermoData


class ExpEntry(PDEntry, MSONable):
    """
    An lightweight ExpEntry object containing experimental data for a
    composition for many purposes. Extends a PDEntry so that it can be used for
    phase diagram generation and reaction calculation.

    Current version works only with solid phases and at 298K. Further
    extensions for temperature dependence are planned.

    Args:
        composition: Composition of the entry. For flexibility, this can take
            the form of all the typical input taken by a Composition, including
            a {symbol: amt} dict, a string formula, and others.
        thermodata: A sequence of ThermoData associated with the entry.
        temperature: A temperature for the entry in Kelvin. Defaults to 298K.
    """

    def __init__(self, composition, thermodata, temperature=298):
        comp = Composition(composition)
        self._thermodata = thermodata
        found = False
        enthalpy = float("inf")
        for data in self._thermodata:
            if data.type == "fH" and data.value < enthalpy and \
                    (data.phaseinfo != "gas" and data.phaseinfo != "liquid"):
                enthalpy = data.value
                found = True
        if not found:
            raise ValueError("List of Thermodata does not contain enthalpy "
                             "values.")
        self.temperature = temperature
        super(ExpEntry, self).__init__(comp, enthalpy)

    def __repr__(self):
        return "ExpEntry {}, Energy = {:.4f}".format(self.composition.formula,
                                                     self.energy)

    def __str__(self):
        return self.__repr__()

    @classmethod
    def from_dict(cls, d):
        thermodata = [ThermoData.from_dict(td) for td in d["thermodata"]]
        return cls(d["composition"], thermodata, d["temperature"])

    def as_dict(self):
        return {"@module": self.__class__.__module__,
                "@class": self.__class__.__name__,
                "thermodata": [td.as_dict() for td in self._thermodata],
                "composition": self.composition.as_dict(),
                "temperature": self.temperature}