Merge pull request #145 from KingsburyLab/bugfix

Fix incorrect display of NH4+, NH3, and other formulas

Author: rkingsbury

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.2] - 2024-07-09
+
+### Fixed
+
+- `standardize_formula`: Fix incorrect display of ammonium/ammonia. Previously, their formulas
+  were shown as "H4N[+1]" and "H3N(aq)", respectively. They now correctly display as NH4 and NH3.
+  Similar fixes were implemented for HPO4[-2] / H2PO4[-1] / H3PO4, formate (HCOO[-1]), oxalate (C2O4[-2]), thicyanate (SCN[-1]), and triiodide (I3[-1]).
+  Fixes #136 (@xiaoxiaozhu123)
+
 ## [1.0.1] - 2024-06-17
 
 ### Added

pyproject.toml

@@ -104,5 +104,5 @@ enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
 warn_unreachable = true
 
 [tool.codespell]
-ignore-words-list = "nd"
+ignore-words-list = "nd,formate"
 skip = "tests/test_files/*,src/pyEQL/database/*"

src/pyEQL/engines.py

@@ -139,7 +139,7 @@ class NativeEOS(EOS):
     def __init__(
         self,
         phreeqc_db: Literal["vitens.dat", "wateq4f_PWN.dat", "pitzer.dat", "llnl.dat", "geothermal.dat"] = "llnl.dat",
-    ):
+    ) -> None:
         """
         Args:
             phreeqc_db: Name of the PHREEQC database file to use for solution thermodynamics
@@ -712,7 +712,7 @@ def equilibrate(self, solution):
         # call to equilibrate can thus result in a slight change in the Solution mass.
         solution.components[solution.solvent] = orig_solvent_moles
 
-    def __deepcopy__(self, memo):
+    def __deepcopy__(self, memo) -> "NativeEOS":
         # custom deepcopy required because the PhreeqPython instance used by the Native and Phreeqc engines
         # is not pickle-able.
         import copy
@@ -736,7 +736,7 @@ def __init__(
         phreeqc_db: Literal[
             "vitens.dat", "wateq4f_PWN.dat", "pitzer.dat", "llnl.dat", "geothermal.dat"
         ] = "phreeqc.dat",
-    ):
+    ) -> None:
         """
         Args:
         phreeqc_db: Name of the PHREEQC database file to use for solution thermodynamics

src/pyEQL/salt_ion_match.py

@@ -21,7 +21,7 @@
 class Salt(MSONable):
     """Class to represent a salt."""
 
-    def __init__(self, cation, anion):
+    def __init__(self, cation, anion) -> None:
         """
         Create a Salt object based on its component ions.
 

src/pyEQL/solute.py

@@ -150,7 +150,7 @@ def as_dict(self):
         return dict(asdict(self).items())
 
     # set output of the print() statement
-    def __str__(self):
+    def __str__(self) -> str:
         return (
             "Species "
             + str(self.formula)

src/pyEQL/solution.py

@@ -57,7 +57,7 @@ def __init__(
         database: str | Path | Store | None = None,
         default_diffusion_coeff: float = 1.6106e-9,
         log_level: Literal["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] | None = "ERROR",
-    ):
+    ) -> None:
         """
         Instantiate a Solution from a composition.
 
@@ -2512,7 +2512,7 @@ def from_file(self, filename: str | Path) -> Solution:
         return loadfn(filename)
 
     # arithmetic operations
-    def __add__(self, other: Solution):
+    def __add__(self, other: Solution) -> Solution:
         """
         Solution addition: mix two solutions together.
 
@@ -2600,18 +2600,18 @@ def __add__(self, other: Solution):
             pE=mix_pE,
         )
 
-    def __sub__(self, other: Solution):
+    def __sub__(self, other: Solution) -> None:
         raise NotImplementedError("Subtraction of solutions is not implemented.")
 
-    def __mul__(self, factor: float):
+    def __mul__(self, factor: float) -> None:
         """
         Solution multiplication: scale all components by a factor. For example, Solution * 2 will double the moles of
         every component (including solvent). No other properties will change.
         """
         self.volume *= factor
         return self
 
-    def __truediv__(self, factor: float):
+    def __truediv__(self, factor: float) -> None:
         """
         Solution division: scale all components by a factor. For example, Solution / 2 will remove half of the moles
         of every compoonents (including solvent). No other properties will change.
@@ -2657,7 +2657,7 @@ def print(
 
             print(f"{i}:\t {amt:0.{places}f}")
 
-    def __str__(self):
+    def __str__(self) -> str:
         # set output of the print() statement for the solution
         l1 = f"Volume: {self.volume:.3f~}"
         l2 = f"Temperature: {self.temperature:.3f~}"

src/pyEQL/utils.py

@@ -9,6 +9,7 @@
 import logging
 from collections import UserDict
 from functools import lru_cache
+from typing import Any
 
 from iapws import IAPWS95, IAPWS97
 from pymatgen.core.ion import Ion
@@ -59,7 +60,39 @@ def standardize_formula(formula: str):
         be enclosed in square brackets to remove any ambiguity in the meaning of the formula. For example, 'Na+',
         'Na+1', and 'Na[+]' will all standardize to "Na[+1]"
     """
-    return Ion.from_formula(formula).reduced_formula
+    sform = Ion.from_formula(formula).reduced_formula
+
+    # TODO - manual formula adjustments. May be implemented upstream in pymatgen in the future
+    # thanks to @xiaoxiaozhu123 for pointing out these issues in
+    # https://github.com/KingsburyLab/pyEQL/issues/136
+
+    # ammonia
+    if sform == "H4N[+1]":
+        sform = "NH4[+1]"
+    elif sform == "H3N(aq)":
+        sform = "NH3(aq)"
+    # phosphoric acid system
+    elif sform == "PH3O4(aq)":
+        sform = "H3PO4(aq)"
+    elif sform == "PHO4[-2]":
+        sform = "HPO4[-2]"
+    elif sform == "P(HO2)2[-1]":
+        sform = "H2PO4[-1]"
+    # thiocyanate
+    elif sform == "CSN[-1]":
+        sform = "SCN[-1]"
+    # triiodide
+    elif sform == "I[-0.33333333]":
+        sform = "I3[-1]"
+    # formate
+    elif sform == "HCOO[-1]":
+        sform = "HCO2[-1]"
+    # oxalate
+    elif sform == "CO2[-1]":
+        sform = "C2O4[-2]"
+
+    # TODO - consider adding recognition of special formulas like MeOH for methanol or Cit for citrate
+    return sform
 
 
 def format_solutes_dict(solute_dict: dict, units: str):
@@ -115,18 +148,18 @@ class FormulaDict(UserDict):
     formula notation (e.g., "Na+", "Na+1", "Na[+]" all have the same effect)
     """
 
-    def __getitem__(self, key):
+    def __getitem__(self, key) -> Any:
         return super().__getitem__(standardize_formula(key))
 
-    def __setitem__(self, key, value):
+    def __setitem__(self, key, value) -> None:
         super().__setitem__(standardize_formula(key), value)
         # sort contents anytime an item is set
         self.data = dict(sorted(self.items(), key=lambda x: x[1], reverse=True))
 
     # Necessary to define this so that .get() works properly in python 3.12+
     # see https://github.com/python/cpython/issues/105524
-    def __contains__(self, key):
+    def __contains__(self, key) -> bool:
         return standardize_formula(key) in self.data
 
-    def __delitem__(self, key):
+    def __delitem__(self, key) -> None:
         super().__delitem__(standardize_formula(key))

tests/test_utils.py

@@ -2,6 +2,7 @@
 Tests of pyEQL.utils module
 
 """
+
 from iapws import IAPWS95, IAPWS97
 from pytest import raises
 
@@ -19,6 +20,18 @@ def test_standardize_formula():
     assert standardize_formula("SO4--") == "SO4[-2]"
     assert standardize_formula("Mg+2") == "Mg[+2]"
     assert standardize_formula("O2") == "O2(aq)"
+    assert standardize_formula("NH4+") == "NH4[+1]"
+    assert standardize_formula("NH3") == "NH3(aq)"
+    assert standardize_formula("HPO4--") == "HPO4[-2]"
+    assert standardize_formula("H2PO4-") == "H2PO4[-1]"
+    assert standardize_formula("SCN-") == "SCN[-1]"
+    assert standardize_formula("I3-") == "I3[-1]"
+    assert standardize_formula("HCOO-") == "HCO2[-1]"
+    assert standardize_formula("CO2-1") == "C2O4[-2]"
+    assert standardize_formula("C2O4--") == "C2O4[-2]"
+    assert standardize_formula("H3PO4") == "H3PO4(aq)"
+    assert standardize_formula("H2SO4") == "H2SO4(aq)"
+    assert standardize_formula("HClO4") == "HClO4(aq)"
 
 
 def test_formula_dict():