Search for Species Data by
Please follow the steps below to
conduct your search (Help):
Chemical Formula Search Help
- Enter a sequence of element symbols followed by numbers
to specify the amounts of desired elements (e.g., C6H6).
- Use correct case for element symbols. If correct case
is not used, the formula may be ambiguous and the interpretation
chosen may not be the desired one.
- Elements may be in any order.
- If only one of a given atom is desired, you may omit
the number after the element symbol.
- Parentheses may be used to group atoms.
- Multiple specifications for an atom will be added.
This means that CH3(CH2)4CH3 will be
treated the same as C6H14.
- To specify one or more of a given atom, use a
question mark (?) after the element symbol.
- To specify any number (including zero) of given
element, use an asterisk (*) after the element symbol.
- To explicitly specify an ion, place the charge at
the end of the formula. If the charge is greater than
one the charge should be included after the +
or - symbol (e.g., C60-2).
|Chemical Formula||Search Specification|
|C2H4||Species with two C, and four H.|
|CH2CH2||Species with two C, and four H.|
|CH3CH||Species with two C, and four H.|
|(CH2)2||Species with two C, and four H.|
|C2H*F?||Species with two C, zero or more H and one or more F.|
- Exactly match the specified isotopes
- When checked, this option indicates that the search
should match isotopes as specified in the search formula.
For example, when this option is not checked a search on
H2 will match species containing
deuterium and tritium atoms. If this option was checked,
deuterium and tritium would be excluded from the search.
- Allow elements not specified in formula
- When checked, this option indicates that species
containing elements not specified in the formula
will also be matched. For example, a search for
Te2 will find all of the species which
contain exactly two tellurium atoms and any number of
other atoms. Checking this option alone is equivalent
to the "partial formula search" previously available
from this site.
- This option indicates that species containg more
atoms than specified of a given element will be matched.
For example, a search for Te with only
this option checked will find all tellurium, ditellurium,
- Exclude ions from the search
- When this option is checked, the search will not
match ions unless a charge is explicitly indicted in
- If one or more of the data types are checked,
the search will be restricted to species which
contain at least one of the data types specified.
- If none of the data types are checked, there
will be no restrictions on the search.
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