bibliottACS Citation Generator — 4th edition
Free, accurate ACS citations in seconds. Built for chemistry, biochemistry, materials science. AI fills in missing metadata; you copy or export.
What is ACS 4th edition?
ACS (4th ed., 2020) is the citation style for American Chemical Society journals (J. Am. Chem. Soc., Chem. Rev., Org. Lett., etc.) and most chemistry programs. It supports three in-text variants: numeric superscript, italicized numbers in parentheses, and author-date — but most ACS journals require numeric.
When to use ACS
- ACS journals and chemistry research papers
- Most US chemistry, biochemistry and chemical engineering programs
- Materials science and polymer chemistry research
ACS quick reference
In-text citation
Numeric superscript ¹ or italicized parenthetical (1) — depends on journal.
The reaction proceeds via a radical mechanism.¹ — or — …radical mechanism (1).
References (numbered in order of citation)
(#) Author, A.; Author, B. Title. Journal Abbrev. Year, volume, pages.
(1) Smith, J. D.; Lee, A. R. The Future of Artificial Intelligence in Academic Research. Nat. Mach. Intell. 2023, 5, 234–245.
(#) Author, A. Title; Publisher: City, Year.
(2) Brown, P. Citation in the Digital Age; Oxford University Press: Oxford, 2021.
Key ACS formatting rules
- Use semicolons between authors, ampersand not used.
- Italicize journal abbreviations (CASSI database).
- Bold the year, italicize volume — house style varies by journal.
- For 11+ authors, list the first 10 then "et al."
Other citation styles
ACS FAQ
ACS lets each journal choose; J. Am. Chem. Soc. bolds the year, others italicize it. The 4th edition documents both patterns.