Suggestions for chemstyle
The following packages have something in common with the package chemstyle. The packages are ordered in decreasing similarity.
- chemscheme: Support for chemical schemes
 - chemcono: Support for compound numbers in chemistry documents
 - chemcompounds: Simple consecutive numbering of chemical compounds
 - lewis: Draw Lewis structures
 - streetex: Structural organic chemistry
 - chemschemex: Typeset and cross-reference chemical schemes based on TikZ code
 - elements: Provides properties of chemical elements
 - proflabo: Draw laboratory equipment
 - chemgreek: Upright Greek letters in chemistry
 - bpchem: Typeset chemical names, formulae, etc.
 - quantum-chemistry-bonn: Use consistent typsetting for quantum chemistry related software
 - carbohydrates: Carbohydrate molecules with chemfig
 - chemexec: Creating (chemical) exercise sheets
 - chemarrow: Arrows for use in chemistry
 - endiagram: Easy creation of potential energy curve diagrams
 - rsc: BibTeX style for use with RSC journals
 - substances: A database of chemicals
 - textopo: Annotated membrane protein topology plots
 - chemarr: Arrows for chemists
 - fancylabel: Complex labelling with LaTeX
 - nucleardata: Provides data about atomic nuclides for documents
 - chemformula: Command for typesetting chemical formulas and reactions
 - chemmacros: A collection of macros to support typesetting chemistry documents
 - bohr: Simple atom representation according to the Bohr model
 - chemsym: Macros for typing chemical symbols
 - chemnum: A method for numbering chemical compounds
 - ghsystem: Globally harmonised system of chemical (etc) naming
 - modiagram: Drawing molecular orbital diagrams
 - mychemistry: Create reaction schemes with LaTeX and chemfig
 - xymtex: Typesetting chemical structures
 - mhchem: Typeset chemical formulae/equations and H and P statements