How to Use an ACS Citation Generator (2025 Rules)

An ACS citation generator turns a DOI into a chemistry reference in a few seconds, and the punctuation, the bold year and the italic volume usually come out right. What it gets wrong sits in the metadata: chemical formulas that lose their subscripts, author lists that run past ten names, a stray period after the DOI, and a mix of abbreviated and full journal names. The rules you are checking against also moved recently. The References chapter of the ACS Guide to Scholarly Communication was revised on April 8, 2025, and the revision made journal abbreviations optional, left article-title capitalization to the writer, and dropped the default access date for online sources. This guide shows real generator output for real DOIs, the current formats to check it against, and ten fixes to make before the reference list goes into your lab report or thesis.

What an ACS citation generator gets from a DOI, and what it cannot

A generator does two jobs. It fetches the metadata a publisher deposited with Crossref when it registered the DOI, then it pours that record into a style template. For ACS, the template is the "American Chemical Society" CSL file from Zotero's style repository. The template knows the element order. It does not know whether the record it was handed is clean.

To see where the errors come from, we ran three DOIs through our own generator on the day this guide was written and compared the output with the references the UC San Diego Library prints for the same articles in its ACS journal article guide. Here is the first one:

` Generated from DOI 10.1021/jacs.4c16977: Ko, S. L.; Dorrell, J. A.; Alter, E. D.; Ta, A. C.; Morris, A. J.; Griffith, K. J. Extreme Defect Tolerance for Electrochemical Intercalation in Wadsley–Roth Structures Demonstrated by Metastable NaNb 7 O 18. Journal of the American Chemical Society 2025, 147 (10), 8513–8522. https://doi.org/10.1021/jacs.4c16977.

As printed in the UCSD guide: Ko, S. L.; Dorrell, J. A.; Alter, E. D.; Ta, A. C.; Morris, A. J.; Griffith, K. J. Extreme Defect Tolerance for Electrochemical Intercalation in Wadsley–Roth Structures Demonstrated by Metastable NaNb7O18. Journal of the American Chemical Society 2025, 147 (10), 8513-8522. https://doi.org/10.1021/jacs.4c16977 `

The author order, the journal name, the bold 2025, the italic 147 and the issue in parentheses all match. Two things do not. The publisher deposited the formula in the Crossref record with the 7 and the 18 tagged as subscripts, and the generator flattened the tags into spaces, giving "NaNb 7 O 18". And the generated reference ends with a period after the DOI, which the UCSD guide's page on DOIs and URLs says not to add, because a reader copying the link picks it up.

The second DOI, a Chemistry of Materials paper with twelve authors, came back with all twelve names. The UCSD guide lists the first ten, then "et al." The third, a Chemical Communications article whose title contains a coordination complex with an italic p, came back as "Na[Tc(CO)(CN p -F-Ar DArF2 ) 4 ]", with the italics, superscript and subscript all gone. None of these problems is visible to the software. All of them are visible to a chemist reading your reference list.

So the working rule for the rest of this guide: trust the generator for element order and typography, and check the metadata yourself.

The 2025 ACS reference rules to check against

You need the target before you can check the output. The authority is the References chapter of the ACS Guide to Scholarly Communication. UC San Diego's guide gives it as revised April 8, 2025, and notes that the chapter's Quick Guide section (4.3.3) is open access and will remain so, while institution-wide access to the full guide ended on December 31, 2025. The UCSD page on the major changes in the 2025 update lists four:

Many course handouts still describe the older rules. The University of Wisconsin–Madison's ACS style guide still points students to the 3rd edition of The ACS Style Guide (2006), and plenty of instructors will still ask for CASSI abbreviations. The 2025 rules widen what is acceptable. They do not overrule a stricter style sheet from your department, so if your handout says abbreviate, abbreviate.

Journal article

Author 1; Author 2; ...; Last Author. Article Title. Journal Title Year, Volume (Issue), Pages or Article Number. DOI or URL

The journal title and volume are italic and the year is bold. A print article is cited the same way without the DOI. Articles that have no page range use the article number, as in this example from the UCSD guide:

Hoogerland, L.; van den Berg, S. P. H.; Suo, Y.; Moriuchi, Y. W.; Zoumaro-Djayoon, A.; Geurken, E.; Yang, F.; Bruggeman, F.; Burkart, M. D.; Bokinsky, G. A temperature-sensitive metabolic valve and a transcriptional feedback loop drive rapid homeoviscous adaptation in Escherichia coli. Nature Communications 2024, 15, 9836. https://doi.org/10.1038/s41467-024-53677-5

Note the italic Escherichia coli inside the title. Species names, Greek letters and formulas keep their formatting in an ACS reference.

Book and chapter

` Author 1; Author 2; ...; Last Author. Book Title, number ed.; Publisher, Year. DOI or URL

Author 1; ...; Last Author. Chapter Title. Book Title; Editor 1, Editor 2, Eds.; Publisher, Year, pp Pages. DOI or URL `

Two details catch generators out. The publisher location is usually left off; UCSD adds it only for a lesser-known publisher or one that would be ambiguous without it. And editors are separated by commas, while authors are separated by semicolons, which the UCSD guide calls an ACS Publications convention.

` Meyers, M. A.; Chawla, K. K. Mechanical Behavior of Materials, 3rd ed.; Cambridge University Press, 2025.

Steinbuch, K. B.; Tor, Y. Isomorphic Fluorescent Nucleoside Analogs. Handbook of Chemical Biology of Nucleic Acids; Sugimoto, N., Ed.; Springer, 2023, pp 473-496. https://doi.org/10.1007/978-981-19-9776-1_17 `

The edition follows the title after a comma and is not italic. A first edition is usually not labeled.

Online sources and preprints

` Author or Organization. Title of Site. URL (accessed YYYY-MM-DD)

Author 1; ...; Last Author. Article Title, Ver. Number. Preprint Server, Date. DOI or URL `

The access date in parentheses is now optional. When you do include one, it goes at the end in year-month-day form. A preprint is cited like a website, with the server (ChemRxiv, arXiv, bioRxiv) in the italic title position and the version number after the title. Our guide to citing websites in ACS style has more worked examples, written against the 2020 guide; the access dates in its examples are now a choice, not a requirement.

In-text numbers

ACS Publications uses superscript numbers in its PDFs and parenthetical numbers in its HTML articles, according to the UCSD guide's in-text citation page, and it does not use author-date. A superscript number goes after the punctuation with no space between them. A parenthetical number goes before the punctuation, with a space before it (1). A source cited again keeps its first number, and three or more consecutive numbers collapse into a range (7-12). Ask your instructor which form they want; generators default to superscript.

Step by step: generating an ACS reference

1. Find the identifier. For a journal article, copy the DOI from the article page, not from a database proxy link. For a book, use the ISBN. For a web page, copy the stable link (a permalink or share link if the site offers one), not a URL with your university's login token in it.
2. Choose the style. Pick "ACS" or "American Chemical Society". Some tools also list journal-specific variants; those are for submitting to a particular ACS journal and may differ in small ways.
3. Generate, then open the article. Keep the article's first page or HTML landing page next to the generated reference. Every check below compares the two.
4. Decide your list-wide choices once. Journal names abbreviated or full, DOI as a link or with the DOI: prefix, titles as published or recapitalized, access dates on web sources or not. Write the four decisions down and apply them to every entry.
5. Run the ten checks. Then paste the list into your document, with the reference numbers in the order the sources first appear in your text.

The two things a generator cannot do at all are steps 4 and 5. It formats each reference in isolation, so it has no idea whether entry 14 matches entry 3.

Ten checks to run on ACS generator output

Checks 3, 4 and 5 come straight from the output we tested. The rest cover choices a generator cannot make for you, because it formats each reference without seeing the others.

1. Use one journal-name form for every entry

The 2025 rule is consistency: all abbreviated or all full. Generators break it because they print whatever the metadata carries. Our generator prints the full title from the DOI record. Add one reference by hand, or import one from a database that supplies the short title, and you end up with Journal of the American Chemical Society in entry 1 and Chem. Mater. in entry 2. Read down the list once, looking only at the italic journal names.

The University of Manitoba's ACS citation guide puts the older version of this problem bluntly: "Citation Generators DO NOT abbreviate the name of the journal which is required in ACS style." Under the 2025 rules a full name is no longer wrong. A mix still is.

2. If you abbreviate, take the abbreviation from CASSI

If your instructor wants abbreviations, look each journal up in CASSI, the CAS Source Index search tool at cassi.cas.org. Journal of the American Chemical Society becomes J. Am. Chem. Soc., and Chemistry of Materials becomes Chem. Mater. One-word titles such as Langmuir, Science and Nature are never abbreviated, and a journal that is not in CASSI is written out in full. Our complete guide to ACS citation format has a table of the common chemistry abbreviations.

One trap here: do not update a journal's name if it has changed since the article was published. Cite the name printed on the article.

3. Restore subscripts, superscripts and italics in titles

The 2025 revision says punctuation, superscripts and subscripts, italicized words and symbols "should be retained," and that you may need to add them back after importing into EndNote, Zotero or another reference manager. Look for:

• Formulas broken by spaces: "NaNb 7 O 18" should be NaNb7O18 with the 7 and 18 set as subscripts.
• Lost italics on species names (Escherichia coli), stereodescriptors (cis, (E)-), and locants like m-terphenyl or p-fluoro.
• Greek letters spelled out or dropped: β-lactams, π-conjugated.

In Word, select the digits and press Ctrl+= for subscript (Ctrl+Shift+= for superscript). In Google Docs the shortcuts are Ctrl+, and Ctrl+.

4. Count the authors

When a work has more than ten authors, the UCSD guide's author page has you list the first ten and then write "et al." The ACS style file our generator uses has no et al. rule for the reference list, so it lists every name; check any other tool the same way. A twelve-author paper should read:

Mu, A. U.; Singh, V. V.; Kim, H.; Lee, D. J.; Kim, N.; Ruff, C. X.; Levy, A.; Young, T. A.; Paesani, F.; Cohen, S. M.; et al. Structure–Activity Relationships in Ether-Functionalized Solid-State Metal–Organic Framework Electrolytes. Chemistry of Materials 2025, 37 (8), 2783-2794. https://doi.org/10.1021/acs.chemmater.4c03384

Note the semicolon before "et al." For a collaboration with hundreds of authors, such as a physics or astronomy consortium, UCSD suggests citing the collaboration itself as the author (STAR Collaboration).

5. Delete the period after the DOI or URL

The UCSD guide says not to put a period or any other punctuation after a DOI or URL. The period belongs after the element that comes before the link: the page range, the date, or a note. Generators that end every entry with a period put one after the link. Delete it.

6. Write every DOI the same way

Since the 2025 revision, the DOI can be the full link (https://doi.org/10.1021/jacs.4c16977) or the prefix form (DOI: 10.1021/jacs.4c16977). Mixing them is the problem. References gathered from more than one tool are where this goes wrong, so check it alongside the journal names. DOIs are not case-sensitive, so a generator that prints "10.1039/d3cc00946g" in lower case has not made an error.

7. Check the typography that the template controls

This one is usually right, but a paste can strip it. The journal title and the volume are italic, the year is bold, the issue sits in parentheses with no italics, and there is a comma after the year and after the volume block. A paste into a plain-text field or an online form can drop the bold and italic, and you will need to reapply them.

8. Decide on access dates, then apply the decision

A DOI never needs an access date. For a URL-only source, the 2025 revision says to judge whether the date adds anything. UCSD's reasoning: a date helps a reader find an archived copy of a page in the Wayback Machine, but it cannot help when the page was never archived, or when the content cannot be reproduced at all, as with generative AI output. Some generators add "(accessed ...)" to every web source automatically. Keep it on pages that change, such as databases and agency pages, and use one form throughout: (accessed 2026-10-26).

9. Remove the publisher location for well-known publishers

The ACS template prints a place whenever the metadata carries one, so a catalog record can give you "Royal Society of Chemistry: Cambridge, 2024". The UCSD guide says you can leave the location out in most cases, and the Manitoba guide names Wiley, Springer and CRC Press as publishers that do not need one. Delete it unless the publisher is obscure or ambiguous.

10. Make sure you are citing the version you read

A DOI lookup returns whatever the DOI points to. If you read a preprint, cite the preprint, with its version number and server. If a published version exists, UCSD recommends finding and citing it instead, which you can check in Google Scholar under the "All versions" link. An article you read online before it had a volume and pages takes the status phrase the publisher used, covered in the next section.

Special cases

Generators handle a standard journal article well. These are the cases where you will be editing the output or building the reference yourself.

Articles published ahead of print (ASAP)

An article posted online before it is assigned to an issue has no volume, issue or pages yet. Replace those three elements with the phrase the publisher uses, such as "ASAP Article," "Early View," "Accepted Manuscript," or "In Press," and keep the year and DOI.

Dommer, A. C.; Amaro, R. E.; Prather, K. A. Understanding Aerosol-Mediated Disease Transmission. ACS Central Science 2025, ASAP Article. https://doi.org/10.1021/acscentsci.5c00364

Before you submit, check whether the article has since been assigned a volume. If it has, update the reference.

Preprints

A preprint has not been peer-reviewed and is not cited like a journal article. The server takes the italic title position, the version number follows the article title, and the full posting date replaces the year. This example comes from the UCSD guide's preprint page:

Sethuraman, S.; Westervelt, D.; Gong, K.; Grassian, V.; McNeil, V. F. Modeling and parameterization of size-dependent processes in multiphase aerosol chemistry, Ver. 2. ChemRxiv, April 20, 2026. https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-q36bp/v2

Our generator returned nothing for this versioned ChemRxiv DOI on the day we tested it, so expect to type some preprint references by hand.

Chapters in a book series

Methods in Enzymology, Annual Review of Physical Chemistry and the ACS Symposium Series sit between books and journals. Generators guess which one they are and often guess differently from one chapter to the next. The UCSD guide allows either form for a numbered series, and the journal form is shorter:

` As a chapter: Offerdahl, E. G.; Arneson, J. B. Formative Assessment to Improve Student Learning in Biochemistry. Biochemistry Education: From Theory to Practice; Bussey, T. J., Cortes, K. L., Austin, R. C., Eds.; ACS Symposium Series, Vol. 1337; American Chemical Society, 2019, pp 197-218. https://doi.org/10.1021/bk-2019-1337.ch009

As a journal article: Offerdahl, E. G.; Arneson, J. B. Formative Assessment to Improve Student Learning in Biochemistry. ACS Symposium Series 2019, 1337, 197-218. https://doi.org/10.1021/bk-2019-1337.ch009 `

Pick one form for each series and use it every time that series appears. For an unnumbered series, the chapter form keeps the volume's own title, which the journal form would lose.

Sources found through JSTOR, HathiTrust or ProQuest

When you read an older article or book through an aggregator, add "(retrieved from Provider)" after the pages, then the link if it is stable and contains no account information. The ACS template has no field for that note, so add it by hand:

Lewis, G. N.; Randall, M. Thermodynamics and the Free Energy of Chemical Substances; McGraw-Hill Book Company, 1923 (retrieved from Hathitrust). https://hdl.handle.net/2027/mdp.39015064498077

Group and organization authors

When no person is named, the organization is the author, highest level first: American Chemical Society, Division of Organic Chemistry. If an organization comes out of the generator with initials, the record entered it as a personal name; retype it as one unit.

AI tools

The UCSD guide notes that there is no consensus on whether to cite generative AI tools at all. It quotes ACS Publications' AI policy, which asks authors to disclose AI use in the Acknowledgment section (or the Methods, for substantial use) and says AI tools cannot be authors. If your instructor wants a reference as well, cite the tool like a website:

ChatGPT-5.2 (AI Chatbot). OpenAI. https://chatgpt.com/ (accessed 2026-04-07)

A reference does not replace the disclosure. Check your course's policy before you use the tool at all.

Common mistakes and how to avoid them

• Mixing abbreviated and full journal names. It happens when references come from two tools, or when some were typed by hand. Fix: choose one form before you start and read down the journal column once at the end.
• Trusting a formula in a title. Crossref records carry subscripts as markup, and our generator flattened it in testing. Fix: search the reference list for any title with a chemical formula, a species name or a Greek letter, and compare it with the article.
• Listing twenty authors. The generator does not apply the ten-author cutoff. Fix: count the semicolons. More than nine means more than ten authors.
• Leaving a period after the link. Fix: end each entry at the last character of the DOI or URL.
• Citing the accepted manuscript after the final version is out. An "ASAP Article" reference from September may have a volume and pages by December. Fix: open each ASAP DOI before you submit.
• Following a 2006 handout and a 2025 generator at once. A handout based on the 3rd edition and a generator built on newer guidance will disagree about abbreviations and article titles. Fix: your instructor's handout decides; the generator is a draft.

Quick-reference table