def _extract_charge(arg: str):
"""
Receive a `str` representing an element, isotope, or ion.
Return a `tuple` containing a `str` that should represent an
element or isotope, and either an `int` representing the
charge or `None` if no charge information is provided. Raise
an `~plasmapy.utils.InvalidParticleError` if charge information
is inputted incorrectly.
"""
invalid_charge_errmsg = (f"Invalid charge information in the particle string '{arg}'.")
if arg.count(' ') == 1: # Cases like 'H 1-' and 'Fe-56 1+'
isotope_info, charge_info = arg.split(' ')
sign_indicator_only_on_one_end = (
charge_info.endswith(('-', '+')) ^
charge_info.startswith(('-', '+')))
just_one_sign_indicator = (
(charge_info.count('-') == 1 and
charge_info.count('+') == 0) or
(charge_info.count('-') == 0 and
charge_info.count('+') == 1))
if not sign_indicator_only_on_one_end and just_one_sign_indicator:
raise InvalidParticleError(invalid_charge_errmsg) from None
charge_str = charge_info.strip('+-')
try:
if roman.is_roman_numeral(charge_info):
Z_from_arg = roman.from_roman(charge_info) - 1
elif '-' in charge_info:
Z_from_arg = - int(charge_str)
elif '+' in charge_info:
Z_from_arg = int(charge_str)
else:
raise InvalidParticleError(invalid_charge_errmsg) from None
except ValueError:
raise InvalidParticleError(invalid_charge_errmsg) from None
elif arg.endswith(('-', '+')): # Cases like 'H-' and 'Pb-209+++'
char = arg[-1]
match = re.match(f"[{char}]*", arg[::-1])
Z_from_arg = match.span()[1]
isotope_info = arg[0:len(arg) - match.span()[1]]
if char == '-':
Z_from_arg = -Z_from_arg
if isotope_info.endswith(('-', '+')):
raise InvalidParticleError(invalid_charge_errmsg) from None
else:
isotope_info = arg
Z_from_arg = None
return isotope_info, Z_from_arg
def _reconstruct_isotope_symbol(element: str, mass_numb: Integral) -> str:
"""
Receive a `str` representing an atomic symbol and an
`int` representing a mass number. Return the isotope symbol
or `None` if no mass number information is available. Raises an
`~plasmapy.utils.InvalidParticleError` for isotopes that have
not yet been discovered.
"""
if mass_numb is not None:
isotope = f"{element}-{mass_numb}"
if isotope == 'H-2':
isotope = 'D'
elif isotope == 'H-3':
isotope = 'T'
if isotope not in _Isotopes.keys():
raise InvalidParticleError(
f"The string '{isotope}' does not correspond to "
f"a valid isotope.")
else:
isotope = None
return isotope
def _extract_mass_number(isotope_info: str):
"""
Receives a string representing an element or isotope.
Return a tuple containing a string that should represent
an element, and either an integer representing the mass
number or None if no mass number is available. Raises an
`~plasmapy.utils.InvalidParticleError` if the mass number
information is inputted incorrectly.
"""
if isotope_info == 'D':
element_info, mass_numb = 'H', 2
elif isotope_info == 'T':
element_info = 'H'
mass_numb = 3
elif isotope_info == 'p':
element_info = 'H'
mass_numb = 1
elif '-' not in isotope_info:
element_info = isotope_info
mass_numb = None
elif isotope_info.count('-') == 1:
element_info, mass_numb_str = isotope_info.split('-')
try:
mass_numb = int(mass_numb_str)
except ValueError:
raise InvalidParticleError(
f"Invalid mass number in isotope string "
f"'{isotope_info}'.") from None
return element_info, mass_numb
def opposite(particle):
try:
opposite_particle = ~particle
except Exception as exc:
raise InvalidParticleError(
f"The unary ~ (invert) operator is unable to find the "
f"antiparticle of {particle}.") from exc
return opposite_particle
def _atomic_number_to_symbol(atomic_numb: Integral):
"""
Return the atomic symbol associated with an integer
representing an atomic number, or raises an
`~plasmapy.utils.InvalidParticleError` if the atomic number does
not represent a known element.
"""
if atomic_numb in _atomic_numbers_to_symbols.keys():
return _atomic_numbers_to_symbols[atomic_numb]
else:
raise InvalidParticleError(f"{atomic_numb} is not a valid atomic number.")
def _get_element(element_info: str) -> str:
"""
Receive a `str` representing an element's symbol or
name, and returns a `str` representing the atomic symbol.
"""
if element_info.lower() in _element_names_to_symbols.keys():
element = _element_names_to_symbols[element_info.lower()]
elif element_info in _atomic_numbers_to_symbols.values():
element = element_info
else:
raise InvalidParticleError(
f"The string '{element_info}' does not correspond to "
f"a valid element.")
return element
def __getitem__(self, value) -> State:
"""Return information for a single ionization level."""
if isinstance(value, slice):
raise TypeError("IonizationState instances cannot be sliced.")
if isinstance(value, Integral) and 0 <= value <= self.atomic_number:
result = State(
value,
self.ionic_fractions[value],
self.ionic_symbols[value],
self.number_densities[value],
)
else:
if not isinstance(value, Particle):
try:
value = Particle(value)
except InvalidParticleError as exc:
raise InvalidParticleError(
f"{value} is not a valid integer charge or "
f"particle.") from exc
same_element = value.element == self.element
same_isotope = value.isotope == self.isotope
has_charge_info = value.is_category(
any_of=["charged", "uncharged"])
if same_element and same_isotope and has_charge_info:
Z = value.integer_charge
result = State(
Z,
self.ionic_fractions[Z],
self.ionic_symbols[Z],
self.number_densities[Z],
)
else:
if not same_element or not same_isotope:
raise AtomicError("Inconsistent element or isotope.")
elif not has_charge_info:
raise ChargeError("No integer charge provided.")
return result
def _parse_and_check_atomic_input(
argument: Union[str, Integral],
mass_numb: Integral = None,
Z: Integral = None):
"""
Parse information about a particle into a dictionary of standard
symbols, and check the validity of the particle.
Parameters
----------
argument : `str` or `int`
String containing information for an element, isotope, or ion
in any of the allowed formats; or an integer representing an
atomic number.
mass_numb : `int`, optional
The mass number of an isotope.
Z : `int`, optional
The integer charge of an ion.
Returns
-------
nomenclature_dict : `dict`
A dictionary containing information about the element, isotope,
or ion. The key ``'symbol'`` corresponds to the particle symbol
containing the most information, ``'element'`` corresponds to
the atomic symbol, ``'isotope'`` corresponds to the isotope
symbol, ``'ion'`` corresponds to the ion symbol, ``'mass_numb'``
corresponds to the mass number, and ``'Z'`` corresponds to the
integer charge. The corresponding items will be given by `None`
if the necessary information is not provided.
Raises
------
`~plasmapy.utils.InvalidParticleError`
If the arguments do not correspond to a valid particle or
antiparticle.
`~plasmapy.utils.InvalidElementError`
If the particle is valid but does not correspond to an element,
ion, or isotope.
`TypeError`
If the argument or any of the keyword arguments is not of the
correct type.
"""
def _atomic_number_to_symbol(atomic_numb: Integral):
"""
Return the atomic symbol associated with an integer
representing an atomic number, or raises an
`~plasmapy.utils.InvalidParticleError` if the atomic number does
not represent a known element.
"""
if atomic_numb in _atomic_numbers_to_symbols.keys():
return _atomic_numbers_to_symbols[atomic_numb]
else:
raise InvalidParticleError(f"{atomic_numb} is not a valid atomic number.")
def _extract_charge(arg: str):
"""
Receive a `str` representing an element, isotope, or ion.
Return a `tuple` containing a `str` that should represent an
element or isotope, and either an `int` representing the
charge or `None` if no charge information is provided. Raise
an `~plasmapy.utils.InvalidParticleError` if charge information
is inputted incorrectly.
"""
invalid_charge_errmsg = (f"Invalid charge information in the particle string '{arg}'.")
if arg.count(' ') == 1: # Cases like 'H 1-' and 'Fe-56 1+'
isotope_info, charge_info = arg.split(' ')
sign_indicator_only_on_one_end = (
charge_info.endswith(('-', '+')) ^
charge_info.startswith(('-', '+')))
just_one_sign_indicator = (
(charge_info.count('-') == 1 and
charge_info.count('+') == 0) or
(charge_info.count('-') == 0 and
charge_info.count('+') == 1))
if not sign_indicator_only_on_one_end and just_one_sign_indicator:
raise InvalidParticleError(invalid_charge_errmsg) from None
charge_str = charge_info.strip('+-')
try:
if roman.is_roman_numeral(charge_info):
Z_from_arg = roman.from_roman(charge_info) - 1
elif '-' in charge_info:
Z_from_arg = - int(charge_str)
elif '+' in charge_info:
Z_from_arg = int(charge_str)
else:
raise InvalidParticleError(invalid_charge_errmsg) from None
except ValueError:
raise InvalidParticleError(invalid_charge_errmsg) from None
elif arg.endswith(('-', '+')): # Cases like 'H-' and 'Pb-209+++'
char = arg[-1]
match = re.match(f"[{char}]*", arg[::-1])
Z_from_arg = match.span()[1]
isotope_info = arg[0:len(arg) - match.span()[1]]
if char == '-':
Z_from_arg = -Z_from_arg
if isotope_info.endswith(('-', '+')):
raise InvalidParticleError(invalid_charge_errmsg) from None
else:
isotope_info = arg
Z_from_arg = None
return isotope_info, Z_from_arg
def _extract_mass_number(isotope_info: str):
"""
Receives a string representing an element or isotope.
Return a tuple containing a string that should represent
an element, and either an integer representing the mass
number or None if no mass number is available. Raises an
`~plasmapy.utils.InvalidParticleError` if the mass number
information is inputted incorrectly.
"""
if isotope_info == 'D':
element_info, mass_numb = 'H', 2
elif isotope_info == 'T':
element_info = 'H'
mass_numb = 3
elif isotope_info == 'p':
element_info = 'H'
mass_numb = 1
elif '-' not in isotope_info:
element_info = isotope_info
mass_numb = None
elif isotope_info.count('-') == 1:
element_info, mass_numb_str = isotope_info.split('-')
try:
mass_numb = int(mass_numb_str)
except ValueError:
raise InvalidParticleError(
f"Invalid mass number in isotope string "
f"'{isotope_info}'.") from None
return element_info, mass_numb
def _get_element(element_info: str) -> str:
"""
Receive a `str` representing an element's symbol or
name, and returns a `str` representing the atomic symbol.
"""
if element_info.lower() in _element_names_to_symbols.keys():
element = _element_names_to_symbols[element_info.lower()]
elif element_info in _atomic_numbers_to_symbols.values():
element = element_info
else:
raise InvalidParticleError(
f"The string '{element_info}' does not correspond to "
f"a valid element.")
return element
def _reconstruct_isotope_symbol(element: str, mass_numb: Integral) -> str:
"""
Receive a `str` representing an atomic symbol and an
`int` representing a mass number. Return the isotope symbol
or `None` if no mass number information is available. Raises an
`~plasmapy.utils.InvalidParticleError` for isotopes that have
not yet been discovered.
"""
if mass_numb is not None:
isotope = f"{element}-{mass_numb}"
if isotope == 'H-2':
isotope = 'D'
elif isotope == 'H-3':
isotope = 'T'
if isotope not in _Isotopes.keys():
raise InvalidParticleError(
f"The string '{isotope}' does not correspond to "
f"a valid isotope.")
else:
isotope = None
return isotope
def _reconstruct_ion_symbol(element: str, isotope: Integral = None, Z: Integral = None):
"""
Receive a `str` representing an atomic symbol and/or a
string representing an isotope, and an `int` representing the
integer charge. Return a `str` representing the ion symbol,
or `None` if no charge information is available.
"""
if Z is not None:
if Z < 0:
sign = '-'
else:
sign = '+'
if isotope is None:
base = element
else:
base = isotope
ion = f"{base} {np.abs(Z)}{sign}"
else:
ion = None
if ion == 'H-1 1+':
ion = 'p+'
return ion
if not isinstance(argument, (str, Integral)): # coverage: ignore
raise TypeError(f"The argument {argument} is not an integer or string.")
arg = _dealias_particle_aliases(argument)
if arg in ParticleZoo.everything - {'p+'}:
if (mass_numb is not None) or (Z is not None):
raise InvalidParticleError(
f"The keywords mass_numb and Z should not be specified "
f"for particle '{argument}', which is a special particle.")
else:
raise InvalidElementError(f"{argument} is not a valid element.")
if isinstance(arg, str) and arg.isdigit():
arg = int(arg)
if isinstance(arg, Integral):
element = _atomic_number_to_symbol(arg)
Z_from_arg = None
mass_numb_from_arg = None
elif isinstance(arg, str):
isotope_info, Z_from_arg = _extract_charge(arg)
element_info, mass_numb_from_arg = \
_extract_mass_number(isotope_info)
element = _get_element(element_info)
if mass_numb is not None and mass_numb_from_arg is not None:
if mass_numb != mass_numb_from_arg:
raise InvalidParticleError(
"The mass number extracted from the particle string "
f"'{argument}' is inconsistent with the keyword mass_numb = "
f"{mass_numb}.")
else:
warnings.warn("Redundant mass number information for particle "
f"'{argument}' with mass_numb = {mass_numb}.",
AtomicWarning)
if mass_numb_from_arg is not None:
mass_numb = mass_numb_from_arg
if Z is not None and Z_from_arg is not None:
if Z != Z_from_arg:
raise InvalidParticleError(
"The integer charge extracted from the particle string "
f"'{argument}' is inconsistent with the keyword Z = {Z}.")
else:
warnings.warn("Redundant charge information for particle "
f"'{argument}' with Z = {Z}.", AtomicWarning)
if Z_from_arg is not None:
Z = Z_from_arg
if isinstance(Z, Integral):
if Z > _Elements[element]['atomic number']:
raise InvalidParticleError(
f"The integer charge Z = {Z} cannot exceed the atomic number "
f"of {element}, which is {_Elements[element]['atomic number']}.")
elif Z <= -3:
warnings.warn(f"Particle '{argument}' has an integer charge "
f"of Z = {Z}, which is unlikely to occur in "
f"nature.", AtomicWarning)
isotope = _reconstruct_isotope_symbol(element, mass_numb)
ion = _reconstruct_ion_symbol(element, isotope, Z)
if ion:
symbol = ion
elif isotope:
symbol = isotope
else:
symbol = element
nomenclature_dict = {
'particle': symbol,
'element': element,
'isotope': isotope,
'ion': ion,
'mass number': mass_numb,
'integer charge': Z,
}
return nomenclature_dict
def stable_isotopes(argument: Union[str, Integral] = None,
unstable: bool = False) -> List[str]:
"""
Return a list of all stable isotopes of an element, or if no input is
provided, a list of all such isotopes for every element.
Parameters
----------
argument: `int` or `str`
A string or integer representing an atomic number or element,
or a string representing an isotope.
unstable: `bool`
If set to `True`, this function will return a list of the
unstable isotopes instead of the stable isotopes.
Returns
-------
StableIsotopes: `list` of strings or empty list
List of all stable isotopes of an element, sorted from lowest
mass number. If an element has no stable isotopes, this
function returns an empty list.
Raises
------
`~plasmapy.utils.InvalidElementError`
If the argument is a valid particle but not a valid element.
`~plasmapy.utils.InvalidParticleError`
If the argument does not correspond to a valid particle.
`TypeError`
If the argument is not a string or integer.
Notes
-----
There are 254 isotopes for which no radioactive decay has been
observed. It is possible that some isotopes will be discovered to
be unstable but with extremely long half-lives. For example,
bismuth-209 was recently discovered to have a half-life of about
1.9e19 years. However, such isotopes can be regarded as virtually
stable for most applications.
See Also
--------
`~plasmapy.atomic.known_isotopes` : returns a list of isotopes that
have been discovered
`~plasmapy.atomic.common_isotopes` : returns isotopes with non-zero
isotopic abundances
Examples
--------
>>> stable_isotopes('H')
['H-1', 'D']
>>> stable_isotopes(44)
['Ru-96', 'Ru-98', 'Ru-99', 'Ru-100', 'Ru-101', 'Ru-102', 'Ru-104']
>>> stable_isotopes('beryllium')
['Be-9']
>>> stable_isotopes('Pb-209')
['Pb-204', 'Pb-206', 'Pb-207', 'Pb-208']
>>> stable_isotopes(118)
[]
Find unstable isotopes using the ``unstable`` keyword.
>>> stable_isotopes('U', unstable=True)[:5] # only first five
['U-217', 'U-218', 'U-219', 'U-220', 'U-221']
"""
# TODO: Allow Particle objects representing elements to be inputs
def stable_isotopes_for_element(argument: Union[str, int],
stable_only: Optional[bool]) -> List[str]:
KnownIsotopes = known_isotopes(argument)
StableIsotopes = [
isotope for isotope in KnownIsotopes
if _Isotopes[isotope]['stable'] == stable_only
]
return StableIsotopes
if argument is not None:
try:
element = atomic_symbol(argument)
isotopes_list = stable_isotopes_for_element(element, not unstable)
except InvalidParticleError:
raise InvalidParticleError("Invalid particle in stable_isotopes")
except InvalidElementError:
raise InvalidElementError(
"stable_isotopes is unable to get isotopes "
f"from an input of: {argument}")
elif argument is None:
isotopes_list = []
for atomic_numb in range(1, 119):
isotopes_list += stable_isotopes_for_element(
atomic_numb, not unstable)
return isotopes_list
def common_isotopes(argument: Union[str, Integral] = None,
most_common_only: bool = False) -> List[str]:
"""
Return a list of isotopes of an element with an isotopic abundances
greater than zero, or if no input is provided, a list of all such
isotopes for every element.
Parameters
----------
argument: `int` or `str`, optional
A string or integer representing an atomic number or element,
or a string representing an isotope.
most_common_only: `bool`
If set to `True`, return only the most common isotope.
Returns
-------
isotopes_list: `list` of `str` or empty `list`
List of all isotopes of an element with isotopic abundances
greater than zero, sorted from most abundant to least
abundant. If no isotopes have isotopic abundances greater
than zero, this function will return an empty list. If no
arguments are provided, then a list of all common isotopes of
all elements will be provided that is sorted by atomic number,
with entries for each element sorted from most abundant to
least abundant.
Raises
------
`~plasmapy.utils.InvalidElementError`
If the argument is a valid particle but not a valid element.
`~plasmapy.utils.InvalidParticleError`
If the argument does not correspond to a valid particle.
`TypeError`
If the argument is not a string or integer.
Notes
-----
The isotopic abundances are based on the terrestrial environment
and may not be appropriate for space and astrophysical applications.
See Also
--------
`~plasmapy.utils.known_isotopes` : returns a list of isotopes that
have been discovered.
`~plasmapy.utils.stable_isotopes` : returns isotopes that are stable
against radioactive decay.
`~plasmapy.utils.isotopic_abundance` : returns the relative isotopic
abundance.
Examples
--------
>>> common_isotopes('H')
['H-1', 'D']
>>> common_isotopes(44)
['Ru-102', 'Ru-104', 'Ru-101', 'Ru-99', 'Ru-100', 'Ru-96', 'Ru-98']
>>> common_isotopes('beryllium 2+')
['Be-9']
>>> common_isotopes('Fe')
['Fe-56', 'Fe-54', 'Fe-57', 'Fe-58']
>>> common_isotopes('Fe', most_common_only=True)
['Fe-56']
>>> common_isotopes()[0:7]
['H-1', 'D', 'He-4', 'He-3', 'Li-7', 'Li-6', 'Be-9']
"""
# TODO: Allow Particle objects representing elements to be inputs
def common_isotopes_for_element(
argument: Union[str, int],
most_common_only: Optional[bool]) -> List[str]:
isotopes = known_isotopes(argument)
CommonIsotopes = [
isotope for isotope in isotopes
if 'abundance' in _Isotopes[isotope].keys()
]
isotopic_abundances = [
_Isotopes[isotope]['abundance'] for isotope in CommonIsotopes
]
sorted_isotopes = [
iso_comp
for (isotope,
iso_comp) in sorted(zip(isotopic_abundances, CommonIsotopes))
]
sorted_isotopes.reverse()
if most_common_only and len(sorted_isotopes) > 1:
sorted_isotopes = sorted_isotopes[0:1]
return sorted_isotopes
if argument is not None:
try:
element = atomic_symbol(argument)
isotopes_list = common_isotopes_for_element(
element, most_common_only)
except InvalidParticleError:
raise InvalidParticleError("Invalid particle")
except InvalidElementError:
raise InvalidElementError(
"common_isotopes is unable to get isotopes "
f"from an input of: {argument}")
elif argument is None:
isotopes_list = []
for atomic_numb in range(1, 119):
isotopes_list += common_isotopes_for_element(
atomic_numb, most_common_only)
return isotopes_list
def known_isotopes(argument: Union[str, Integral] = None) -> List[str]:
"""Return a list of all known isotopes of an element, or a list
of all known isotopes of every element if no input is provided.
Parameters
----------
argument: `int` or `str`, optional
A string representing an element, isotope, or ion or an
integer representing an atomic number
Returns
-------
isotopes_list: `list` containing `str` items or an empty `list`
List of all of the isotopes of an element that have been
discovered, sorted from lowest mass number to highest mass
number. If no argument is provided, then a list of all known
isotopes of every element will be returned that is sorted by
atomic number, with entries for each element sorted by mass
number.
Raises
------
`~plasmapy.utils.InvalidElementError`
If the argument is a valid particle but not a valid element.
`~plasmapy.utils.InvalidParticleError`
If the argument does not correspond to a valid particle.
`TypeError`
If the argument is not a `str` or `int`.
Notes
-----
This list returns both natural and artificially produced isotopes.
See Also
--------
`~plasmapy.atomic.common_isotopes` : returns isotopes with non-zero
isotopic abundances.
`~plasmapy.atomic.stable_isotopes` : returns isotopes that are
stable against radioactive decay.
Examples
--------
>>> known_isotopes('H')
['H-1', 'D', 'T', 'H-4', 'H-5', 'H-6', 'H-7']
>>> known_isotopes('helium 1+')
['He-3', 'He-4', 'He-5', 'He-6', 'He-7', 'He-8', 'He-9', 'He-10']
>>> known_isotopes()[0:10]
['H-1', 'D', 'T', 'H-4', 'H-5', 'H-6', 'H-7', 'He-3', 'He-4', 'He-5']
>>> len(known_isotopes()) # the number of known isotopes
3352
"""
# TODO: Allow Particle objects representing elements to be inputs
def known_isotopes_for_element(argument):
element = atomic_symbol(argument)
isotopes = []
for isotope in _Isotopes.keys():
if element + '-' in isotope and isotope[0:len(element)] == element:
isotopes.append(isotope)
if element == 'H':
isotopes.insert(1, 'D')
isotopes.insert(2, 'T')
mass_numbers = [mass_number(isotope) for isotope in isotopes]
sorted_isotopes = [
mass_number
for (isotope, mass_number) in sorted(zip(mass_numbers, isotopes))
]
return sorted_isotopes
if argument is not None:
try:
element = atomic_symbol(argument)
isotopes_list = known_isotopes_for_element(element)
except InvalidElementError:
raise InvalidElementError("known_isotopes is unable to get "
f"isotopes from an input of: {argument}")
except InvalidParticleError:
raise InvalidParticleError("Invalid particle in known_isotopes.")
elif argument is None:
isotopes_list = []
for atomic_numb in range(1, len(_Elements.keys()) + 1):
isotopes_list += known_isotopes_for_element(atomic_numb)
return isotopes_list
def get_particle(argname, params, already_particle, funcname):
argval, Z, mass_numb = params
# Convert the argument to a Particle object if it is not
# already one.
if not already_particle:
if not isinstance(argval, (numbers.Integral, str, tuple, list)):
raise TypeError(
f"The argument {argname} to {funcname} must be "
f"a string, an integer or a tuple or list of them "
f"corresponding to an atomic number, or a "
f"Particle object.")
try:
particle = Particle(argval, Z=Z, mass_numb=mass_numb)
except InvalidParticleError as e:
raise InvalidParticleError(_particle_errmsg(
argname, argval, Z, mass_numb, funcname)) from e
# We will need to do the same error checks whether or not the
# argument is already an instance of the Particle class.
if already_particle:
particle = argval
# If the name of the argument annotated with Particle in the
# decorated function is element, isotope, or ion; then this
# decorator should raise the appropriate exception when the
# particle ends up not being an element, isotope, or ion.
cat_table = [
('element', particle.element, InvalidElementError),
('isotope', particle.isotope, InvalidIsotopeError),
('ion', particle.ionic_symbol, InvalidIonError),
]
for category_name, category_symbol, CategoryError in cat_table:
if argname == category_name and not category_symbol:
raise CategoryError(
f"The argument {argname} = {repr(argval)} to "
f"{funcname} does not correspond to a valid "
f"{argname}.")
# Some functions require that particles be charged, or
# at least that particles have charge information.
_integer_charge = particle._attributes['integer charge']
must_be_charged = 'charged' in require
must_have_charge_info = set(any_of) == {'charged', 'uncharged'}
uncharged = _integer_charge == 0
lacks_charge_info = _integer_charge is None
if must_be_charged and (uncharged or must_have_charge_info):
raise ChargeError(f"A charged particle is required for {funcname}.")
if must_have_charge_info and lacks_charge_info:
raise ChargeError(f"Charge information is required for {funcname}.")
# Some functions require particles that belong to more complex
# classification schemes. Again, be sure to provide a
# maximally useful error message.
if not particle.is_category(require=require, exclude=exclude, any_of=any_of):
raise AtomicError(
_category_errmsg(particle, require, exclude, any_of, funcname))
return particle
