American Chemical Society (ACS) Citation Style: Detailed Guide

Introduction

ACS (American Chemical Society) style is a widely used citation and formatting style in chemistry and related scientific fields. It provides clear guidelines for citing sources and formatting scientific documents, ensuring consistency and accuracy in chemical literature. This document offers a concise overview of ACS citation style, covering its core principles, in-text citation rules, reference list formatting, and examples for various publication types.

ACS Citation Systems

ACS style offers three main ways to cite sources in the text:

1. Numeric (superscript): A superscript number is used in the text, corresponding to a numbered entry in the reference list.

   Example: …as demonstrated in a recent study.¹

2. Numeric (italic, in parentheses): An italicized number in parentheses is used in the text, corresponding to a numbered entry in the reference list.

   Example: …as demonstrated in a recent study (1).

3. Author-Date: The author’s last name and the year of publication are used in parentheses in the text, corresponding to an alphabetical entry in the reference list.

   Example: …as demonstrated in a recent study (Smith, 2023).

Consistency is key: Choose one system and use it consistently throughout your paper.

In-Text Citation Rules

Numeric System (Superscript or Italic, in Parentheses)

• References are numbered consecutively in the order they are first cited in the text.

• The number corresponds to the full citation in the numbered reference list.

  Examples:

  • The reaction was observed to proceed rapidly.¹
  • Previous research supports this finding (2).

• Multiple Citations: Use a hyphen for consecutive numbers and commas for non-consecutive numbers.

  Example: …several studies have confirmed this.^3-5,8

• Author Named in Text: If the author’s name is mentioned in the text, the citation number follows the author’s name.

  Example: Smith⁶ reported that…

Author-Date System

• In-text citations consist of the author’s last name and the year of publication in parentheses.

  Example: (Smith, 2023)

• If the author’s name is mentioned in the text, only the year is needed in parentheses.

  Example: Smith (2023) reported that…

• Multiple Authors:

  • Two Authors: (Smith and Jones, 2023)
  • More than Two Authors: (Smith et al., 2023)

• No Author: Use a shortened title and year.

  Example: ("New Discoveries," 2023)

Reference List

Numeric System

• The reference list is titled "References" and is ordered numerically based on the order of appearance in the text.

Author-Date System

• The reference list is titled "References" and is arranged alphabetically by the author’s last name.

General Reference List Formatting Rules

• Author(s): For journal articles and books, list author surnames followed by initials. For multiple authors, separate names with semicolons. For more than 10 authors, list the first 10 followed by "et al."
• Journal Titles: Journal titles are abbreviated according to the Chemical Abstracts Service Source Index (CASSI) or other standard abbreviations.
• Punctuation: Use periods after author names, article titles, and book titles. Commas separate elements within a citation.
• Online Sources: Include a DOI (Digital Object Identifier) if available. If no DOI, include the URL.

Publication Types and Formatting

Articles (Scientific Journals, Preprints, Magazines, and Newspapers)

Journal Articles

Basic Format (Numeric):

1. Author, A. A.; Author, B. B. Title of Article. Abbreviated Journal Title Year, Volume (Issue), pages. DOI.

Example (Numeric):

1. Tan, G. Y.; Das, M.; Keum, H.; Bellotti, P.; Daniliuc, C.; Glorius, F. Photochemical Single-Step Synthesis of β-Amino Acid Derivatives from Alkenes and (Hetero)arenes. Nature Chem. 2022, 14 (10), 1174−1184. DOI: 10.1038/s41557-022-01008-w.

Basic Format (Author-Date):

Author, A. A.; Author, B. B. (Year). Title of Article. Abbreviated Journal Title, Volume(Issue), pages. DOI.

Example (Author-Date):

Tan, G. Y.; Das, M.; Keum, H.; Bellotti, P.; Daniliuc, C.; Glorius, F. (2022). Photochemical Single-Step Synthesis of β-Amino Acid Derivatives from Alkenes and (Hetero)arenes. Nature Chem., 14(10), 1174−1184. DOI: 10.1038/s41557-022-01008-w.

Journal Article with Article Number:

1. Westermayr, J.; Gastegger, M.; Schütt, K. T.; Maurer, R. J. Perspective on Integrating Machine Learning into Computational Chemistry and Materials Science. J. Chem. Phys. 2021, 154 (23), 230903. DOI: 10.1063/5.0047760.

Journal Article Early Publication (Article ASAP):

1. Cheng, S.; Xu, Y.; Kang, M.; Zhu, W.; Wang, L.; Fu, P. Aurovertins from a Marine-Derived Penicillium Species and Nonenzymatic Reactions in Their Formation. J. Nat. Prod. 2025, ASAP Article. DOI: 10.1021/acs.jnatprod.4c01436.

Preprints

Basic Format (Numeric):

1. Author, A. A. Title of Preprint. Preprint Server, City, State, Month Day, Year. DOI.

Example (Numeric):

1. Deysher, G.; Oh, J. A. S.; Chen, Y.-T.; Sayahpour, B.; Ham, S.-Y.; Cheng, D.; Ridley, P.; Cronk, A.; Lin, S. W.-H.; Qian, K.; Nguyen, L. H. B.; Jang, J.; Meng, Y. S. An Anode-Free Sodium All-Solid-State Battery, Ver. 1. ChemRxiv, November 23, 2023. DOI: 10.26434/chemrxiv-2023-tkcd9.

Magazines

Basic Format (Numeric):

1. Author, A. A. Title of Article. Magazine Title, Month Day, Year, pages.

Example (Numeric):

1. Patel, P. Mighty MXenes: Ready to Roll. C&EN Global Enterprise 2024, 102 (9), 26−32. DOI: 10.1021/cen-10209-cover.

Newspapers

Basic Format (Numeric):

1. Author, A. A. Title of Article. Newspaper Title, Month Day, Year, pages.

Example (Numeric):

1. Demming, A. ‘Doing Something for the Real World’: How 1,000 UK Schoolkids Helped Crack a Crystals Conundrum. Guardian, March 2, 2024. https://www.theguardian.com/science/2024/mar/02/doing-something-for-the-real-world-how-1000-uk-schoolkids-helped-crack-a-crystals-conundrum.

Books

Basic Format (Numeric):

1. Author, A. A. Title of Book, Edition; Publisher: City, State, Year.

Example (Numeric):

1. Frankel, F. Steeped: The Chemistry of Tea; Royal Society of Chemistry, 2024.

Book with Edition:

1. Atkins, P. Concepts in Physical Chemistry, 2nd ed.; Royal Society of Chemistry, 2024.

Book Chapter:

1. Schmitz, C.; Cremmans, K.; Bissadi, G. Application of Machine Learning Algorithms for Use in Material Chemistry. In Computational and Data-Driven Chemistry Using Artificial Intelligence: Fundamentals, Methods and Applications; Akitsu, T., Ed.; Elsevier, 2022; pp 161−192. DOI: 10.1016/B978-0-12-822249-2.00001-3.

Book with Editors:

1. Mom the Chemistry Professor: Personal Accounts and Advice from Chemistry Professors Who Are Mothers, 2nd ed.; Woznack, K., Charlebois, A., Cole, R. S., Marzabadi, C. H., Webster, G., Eds.; Springer, 2018. DOI: 10.1007/978-3-319-78972-9.

Translated Book:

1. Djerassi, C.; Hoffmann, R. Oxygène pièce en 1 acte; Aimée. K., Kornprobst, J.-M., Transl.; Presses Universitaires du Mirail: Toulouse, 2003 (originally published as Oxygen: A Play in Two Acts; Wiley, 2001).

Other Common Source Types

Websites

Basic Format (Numeric):

1. Author, A. A. Title of Page. Website Name. URL (accessed Month Day, Year).

Example (Numeric):

1. American Chemical Society. About ACS. ACS.org. https://www.acs.org/about.html (accessed July 1, 2025).

Theses and Dissertations

Basic Format (Numeric):

1. Author, A. A. Title of Thesis/Dissertation; Degree Type, University, City, State, Year.

Example (Numeric):

1. Smith, J. D. Synthesis of Novel Organic Compounds; Ph.D. Dissertation, University of California, Berkeley, CA, 2023.

Patents

Basic Format (Numeric):

1. Inventor, A. A.; Inventor, B. B. Title of Patent. Patent Number, Date.

Example (Numeric):

1. Engelhardt, T. P.; et al. Diabetes Manager for Glucose Testing and Continuous Glucose Monitoring. U.S. Patent US10568511B2, February 25, 2020.

This guide provides a concise overview of American Chemical Society (ACS) citation style. For more detailed information and specific examples, always consult the official ACS Guide to Scholarly Communication.