Update C[13] neutron scattering cross sections

ChangeLog.rst

@@ -23,6 +23,16 @@ Known issues
 Change history
 ==============
 
+2026-02-13 R2.0.3
+-----------------
+
+Modified:
+
+* Update b_c bp bm and incoherent attributes for C-13
+* Update nuclear_spin for Se-77 Hf-177 W-182
+* Add comparison tables checking b_c and σ_i against b+ and b-
+* Add type hinting to many of the functions
+
 2024-12-19 R2.0.2
 -----------------
 

doc/sphinx/conf.py

@@ -50,6 +50,7 @@
     ('py:class', 'type'),
     ('py:class', 'object'),
 
+    ('py:class', 'collections.abc.Buffer'),
     ('py:class', 'collections.abc.Callable'),
     ('py:class', 'collections.abc.Iterator'),
     ('py:class', 'collections.abc.Sequence'),
@@ -59,6 +60,7 @@
     ('py:class', 'numpy.ndarray'),
     ('py:class', 'numpy.float64'),
     ('py:class', 'numpy._typing._array_like._Buffer'),
+    ('py:class', 'numpy._typing._array_like._ScalarType_co'),
     ('py:class', 'numpy._typing._array_like._SupportsArray'),
     ('py:class', 'numpy._typing._array_like._ScalarT'),
     ('py:class', 'numpy._typing._nested_sequence._NestedSequence'),

periodictable/activation.py

@@ -972,8 +972,7 @@ def init(table, reload=False):
             columns = row.split('\t')
             if columns[0].strip() in ('', 'xx'):
                 continue
-            columns = [c[1:-1] if c.startswith('"') else c
-                    for c in columns]
+            columns = [c[1:-1] if c.startswith('"') else c for c in columns]
             #print columns
             for c in INT_COLUMNS:
                 columns[c] = int(columns[c])

periodictable/core.py

@@ -59,7 +59,7 @@
 __docformat__ = 'restructuredtext en'
 __all__ = ['delayed_load', 'define_elements', 'get_data_path',
            'default_table', 'change_table',
-           'Ion', 'Isotope', 'Element', 'PeriodicTable',
+           'Ion', 'IonSet', 'Isotope', 'Element', 'PeriodicTable',
            'isatom', 'iselement', 'isisotope', 'ision']
 
 from pathlib import Path
@@ -653,16 +653,18 @@ def __repr__(self) -> str:
         return repr(self.element)+'.ion[%d]'%self.charge
     def __reduce__(self):
         try:
-            return _make_isotope_ion, (self.element.table,
-                                       self.element.number,
-                                       self.element.isotope,
-                                       self.charge)
+            iso = cast("Isotope", self.element)
+            return _make_isotope_ion, (iso.table, iso.number, iso.isotope, self.charge)
         except Exception:
-            return _make_ion, (self.element.table,
-                               self.element.number,
-                               self.charge)
+            el = cast("Element", self.element)
+            return _make_ion, (el.table, el.number, self.charge)
 
 class IonSet:
+    """
+    The set of ions associated with an element or isotope.
+
+    This is a dictionary interface indexed by ion charge.
+    """
     element_or_isotope: Union["Element", "Isotope"]
     ionset: dict[int, "Ion"]
 

periodictable/cromermann.py

@@ -190,6 +190,7 @@ def _update_cmformulas() -> None:
     #   #N 11
     #   #L a1 a2 a3 a4 a5 c b1 b2 b3 b4 b5
     #    <a1 a2 a3 a4 a5> <c> <b1 b2 b3 b4 b5>
+    symbol = None
     with open(path) as fp:
         for line in fp:
             if line.startswith("#S"):

periodictable/formulas.py

@@ -90,6 +90,7 @@ def mix_by_weight(*args, **kw) -> "Formula":
     return result
 
 def _mix_by_weight_pairs(pairs: list[tuple["Formula", float]]) -> "Formula":
+    from .formulas import Formula # For running as __main__
 
     # Drop pairs with zero quantity
     # Note: must be first statement in order to accept iterators
@@ -175,6 +176,7 @@ def mix_by_volume(*args, **kw) -> "Formula":
     return result
 
 def _mix_by_volume_pairs(pairs: list[tuple["Formula", float]]) -> "Formula":
+    from .formulas import Formula # For running as __main__
 
     # Drop pairs with zero quantity
     # Note: must be first statement in order to accept iterators
@@ -285,6 +287,8 @@ def formula(
     The representations are simple, but preserve some of the structure for
     display purposes.
     """
+    from .formulas import Formula # For running as __main__
+
     structure: Structure
     if compound is None or compound == '':
         structure = tuple()
@@ -704,7 +708,7 @@ def _isotope_substitution(compound: "Formula", source: Atom, target: Atom, porti
 
 # TODO: Grammar should be independent of table
 # TODO: Parser can't handle meters as 'm' because it conflicts with the milli prefix
-LENGTH_UNITS = {'nm': 1e-9, 'um': 1e-6, 'mm': 1e-3, 'cm': 1e-2}
+LENGTH_UNITS = {'nm': 1e-9, 'um': 1e-6, 'μm': 1e-6, 'mm': 1e-3, 'cm': 1e-2}
 MASS_UNITS = {'ng': 1e-9, 'ug': 1e-6, 'mg': 1e-3, 'g': 1e+0, 'kg': 1e+3}
 VOLUME_UNITS = {'nL': 1e-9, 'uL': 1e-6, 'mL': 1e-3, 'L': 1e+0}
 LENGTH_RE = '('+'|'.join(LENGTH_UNITS.keys())+')'
@@ -909,7 +913,7 @@ def convert_by_layer(string, location, tokens):
         fract = []
         for p1, p2 in zip(tokens[0::2], tokens[1::2]):
             if isinstance(p1, Formula):
-                f = p1.absthick * float(p2)
+                f = p1.thickness * float(p2)
                 p = p1
             else:
                 f = float(p1[0]) * LENGTH_UNITS[p1[1]]