SciFinder: References

How to use the world's largest chemical information database to find chemical references, compounds, and reactions.

Search Steps

Steps in a SciFinder  References: Research Topic search, which'll search for references/citations.

  1. Use best terms.  Info on this page'll help you choose good keywords.
  2. SciFinder search algorithm identifies "concepts", and then constructs a "pick list" of results based on concepts and syntax.
  3. Select one or more results from the pick list.
  4. Use Analyze / Refine / Categorize to focus or limit results.


A list of important search points unique to SciFinder -- these apply to no other databases or search engines:

  • SciFinder uses a natural language query algorithm, breaking a search query into concepts, searching them against the database indexes, and then presenting you with a selection of result options.
  • Slight differences in search phrasing will impact your results.  Try searching different ways.
  • Avoid long complex searches.  Keep it simple.  Use 3-4 concepts (the system limit is 7).
  • Use CAS Registry numbers when searching.
  • You must search for synonyms in parentheses following the search word, separate them with commas. Example: chromium sulfate and humans (men, women)
  • A search for metal, for example, will not automatically search for narrower terms, such as gold, silver, etc.
  • Boolean operators AND and OR do not work in SciFinder; NOT will eliminate things you don't want.
  • Certain words, such as a, an, the, effect, results, are ignored.  Figure out ignored terms by looking at search results.
  • To search an exact phrase, type the phrase without quotation marks (which are ignored), and select the first option in the results list: "X references were found containing 'A B C' as entered." You will only see this option if there was an exact match of your search string in the database. Note that none of the algorithmic processes described below will have been performed on this exact "as entered" phrase.
  • SciFinder is case insensitive.  3DAP = 3dap.
  • SciFinder recognizes and translates some abbreviations. Examples: 'NMR' = 'nuclear magnetic resonance'; 'detn' = 'determination'; 'color' = 'colour' etc. Abbreviations that are ambiguous or non-standard will not be translated in this way. CAS has standard abbreviations for a large number of frequently used words, and these are always translated for you.
  • Automatically searches for British and American spellings (color/colour, flavor/flavour, calibre/caliber, centre/center, fibre/fiber, litre/liter,etc.).
  • Auto-truncates or searches for different word endings automatically.  For example, a search of oxidation will also pull in oxidant, oxidative, oxidized, and oxidizer.  If this retrieves irrelevant results, redo your search and NOT out unwanted terms.
  • SciFinder's secret dictionary connects some synonyms.  Cancer finds neoplasm, dairy finds milk, Antabuse finds 97-77-8 and N,N,N',N'-tetraethyl-thioperoxydicarbonic diamide.  This is very valuable for substance searches. 

Search Rules

1.   Use best terms

2.   Use prepositions

3.   Use parenthetical "OR"

Use Best Terms

The first rule is deceptively simple -- use best terms.  It is not as simple, however, to execute; it is hard to know which term will be "best".

There are two types of "best terms": The terms that SciFinder uses for a concept (indexing and supplementary terms) and the terms that authors use (words in the article title and abstract). 

Identifying best terms depends on your chemical knowledge -- as this improves, so, too, will your searches.

Experiment.  Try different words to find what works best.  Look at the terms used in your best search results, in particular the Indexing concepts and  terms in the title and abstract.  Incorporate these new terms into your search.  It may take several searches (or even weeks or months) to find the best terms. 

Be aware that CAS Registry Numbers are almost always better search terms than common names. An exception to this would be a recent reference that has not yet been assigned a CAS Registry Number.

Chemical Abstracts (aka SciFinder) has a long history of using abbreviations, beginning when printed page space was valuable. Even in the electronic age,  Chemical Abstracts continues to use abbreviations. Knowing CAS Abbreviations aids searches.

Sometimes abbreviations are better search terms;  LCAO, for example,  is better than "linear combination of atomic orbitals". In contrast, HOMO and "highest occupied molecular orbital" are treated identically by SciFinder.

Analyze, Refine, Categorize


  • Best if you want to know more about your search results
  • Can be very slow
  • Most useful => Index terms, Authors, Company/Organizations, Journal Title, CA Section, Year
  • Analyze by Year and sort the results "alphabetically" to see how much research has been done on a topic as a function of time. Some topics are on the rise (gold nanoparticles) while other topics have have waxed and waned over the years (e.g., Wolff reduction, Clemmensen reduction).


  • Best if you know how you want to limit your search
  • Fast
  • Most useful => Publication Type for reviews
  • The keyword limit becomes an "AND" search. It is usually better to revise your search instead and use a preposition with the new concept.


  • Best if you want to see how Index terms and CAS Registry Numbers fit into categories
  • This is a highly recommended "Discovery Tool". Use it to learn more about the search results.
  • Fairly fast
  • Can only be run on < 5,000 references
  • Generates a pick list of index terms & CAS Registry numbers
  • Especially useful to find better keywords to search in SciFinder

Thank You

Content from this page is from Auburn University's SciFinder LibGuide, by Bob Buchanan, who kindly gave us his permission to re-use it. 

Use Prepositions

Using prepositions in SciFinder results in better search results. 

Prepositions invoke the "closely associated" operator, which is a powerful tool.   

In SciFinder,  two concepts "closely associated" will be found together in the title of the article, the same sentence in the abstract, the same index term, the same CAS Registry number (and its free-text modifier), or in the list of Supplementary Terms. 

There is no guarantee that concepts "closely associated" will be the best, but it is more likely.

To see how SciFinder searches differently with/without prepositions, compare these three searches:

  • hydrogen storage metal hydrides

  • hydrogen storage with metal hydrides
  • hydrogen storage and metal hydrides

Be aware that prepositions are not analyzed for their linguistic meaning. In SciFinder, 'determination of arsenic' is the same as 'determination in arsenic' unless you choose the more restrictive "as entered" phrase results.

Use Parenthetical OR

SciFinder does not interpret parentheses in the usual way.

Instead, SciFinder sees an implied Boolean OR.

For example, "mercaptan (thiol) with electron transfer" would be interpreted by SciFinder as meaning ... "mercaptan with electron transfer OR thiol with electron transfer".

Do not use OR and AND Boolean operators in SciFinder; they will give quizzical results when used in tandem.  Instead, place synonyms after your search term, in parenthesis:  mercaptan (thiol).

Combine Searches

Combining searches can be a good way to narrow a search.

  1. Save the results from a search
  2. Run another search
  3. From the Tools pull-down menu (top of page), select "Combine Answer Sets"
  4. Choose the previously saved search
  5. Choose either Combine (OR), Intersect (AND), or one of the two Exclude (NOT) options