LaTeX Subscripts and Superscripts: Complete Guide

Subscripts and superscripts are fundamental to mathematical and scientific writing in LaTeX. This comprehensive guide covers everything from basic syntax to advanced techniques for complex indices, nested scripts, and field-specific notation.

Basic Subscript and Superscript Syntax

In LaTeX, subscripts use the underscore _ and superscripts use the caret ^:

Single Character Scripts

Both Subscript and Superscript

The order doesn’t matter: x_i^2 and x^2_i produce the same result.

Multi-Character Subscripts and Superscripts

When your subscript or superscript has multiple characters, wrap them in curly braces { }:

Without braces, only the first character is affected:

Nested Subscripts and Superscripts

You can nest subscripts and superscripts by using additional _ and ^ within braces:

Subscripts on Subscripts

Superscripts on Superscripts

Mixed Nesting

Limits, Sums, and Integrals

Subscripts and superscripts are crucial for notation involving sums, products, integrals, and limits:

Summation

Product

Integrals

Limits

Text in Subscripts and Superscripts

For multi-letter text (not variables), use \text{} or \mathrm{}:

Without \text, letters are treated as separate variables:

Primes and Derivatives

Prime notation uses the apostrophe ' which is treated as a superscript:

Combining primes with other superscripts:

Tensor Notation

Tensors often require both upper and lower indices (contravariant and covariant):

Einstein Summation

Chemical Formulas

Subscripts are essential for chemical notation. Use text mode for the subscripts:

Matrix and Vector Indices

Matrix Elements

Vector Components

Sequences and Series

Best Practices

Common Commands Reference

Field-Specific Examples

Physics: Kinematics

Computer Science: Big O Notation

Statistics: Expected Value

Linear Algebra: Eigenvalues

Mastering subscripts and superscripts is essential for any technical or scientific writing in LaTeX. Whether you’re working with simple indices, complex tensor notation, or chemical formulas, these techniques will help you create clear and professional documents. Remember to use braces for multi-character scripts, text mode for words, and maintain consistency throughout your work.