Suggestions for isotope

The following packages have something in common with the package isotope. The packages are ordered in decreasing similarity.

Package tensor: Typeset tensors
Package tensind: Typeset tensors
Package nuc: Notation for nuclear isotopes
Package realscripts: Access OpenType subscript and superscript glyphs
Package leftindex: Left indices with better spacing
Package fouridx: Left sub- and superscripts in maths mode
Package leftidx: Left and right subscripts and superscripts in math mode
Package subdepth: Unify maths subscript height
Package subsupscripts: A range of sub- and superscript commands
Package altsubsup: Subscripts and superscripts with square brackets
Package spbmark: Customize superscripts and subscripts
Package tensorstyles: A package separating the content of tensors from their forms
Package slashed: Put a slash through characters
Package simpler-wick: Simpler Wick contractions
Package simplewick: Simple Wick contractions
Package braket: Dirac bra-ket and set notations
Package shuffle: A symbol for the shuffle product
Package upgreek: Upright Greek letters
Package babel-esperanto: Babel support for Esperanto
Package feynmf: Macros and fonts for creating Feynman (and other) diagrams
Package dotlessj: Generates a dot-less j
Package siunitx: A comprehensive (SI) units package
Package chemarr: Arrows for chemists
Package centernot: Centred \not command
Package amsrefs: A LaTeX-based replacement for BibTeX
Package eqnlines: Single- and multiline equations
Package acronym: Expand acronyms at least once
Package appendix: Extra control of appendices
Package algorithmicx: The algorithmic style you always wanted
Package algorithms: A suite of tools for typesetting algorithms in pseudo-code
Package bxcoloremoji: Use color emojis more conveniently