RDKit-powered cheminformatics directly inside Microsoft Excel. Compute molecular properties, render 2D structures, and run custom Excel formulas — all from a lightweight local server with no cloud dependency.
This tool is part of my ongoing research work in computational chemistry and drug discovery. It was built to reduce the friction of moving between cheminformatics tools and spreadsheets during lead optimisation and ADMET analysis workflows.
Inputs, suggestions, and contributions are very welcome. If you use this in your research, encounter bugs, or have ideas for new features — please open an issue or start a discussion.
Use cheminformatics directly in cells — just like any built-in Excel function:
| Formula | Returns |
|---|---|
=CHEM.MW(A2) |
Molecular weight (Da) |
=CHEM.LOGP(A2) |
Lipophilicity (LogP) |
=CHEM.TPSA(A2) |
Topological polar surface area |
=CHEM.HBD(A2) |
Hydrogen bond donor count |
=CHEM.HBA(A2) |
Hydrogen bond acceptor count |
=CHEM.LIPINSKI(A2) |
Lipinski Rule of 5 — PASS / FAIL |
=CHEM.QED(A2) |
Quantitative estimate of drug-likeness (0–1) |
=CHEM.SCAFFOLD(A2) |
Murcko scaffold SMILES |
=CHEM.SMI2IMAGE(A2) |
Renders a 2D structure image into the calling cell |
All formulas accept a SMILES string (or a cell reference to one) and update live.
Select a column of SMILES strings and click:
- Compute Properties — writes MW, LogP, TPSA, HBD, HBA, RotBonds, Lipinski, and QED into adjacent columns, aligned row-by-row. Header rows (e.g. "SMILES") are automatically skipped.
- Embed Structure Images — renders each SMILES as a 250×200 px PNG and embeds it directly into its cell. The row and column are auto-resized to fit the image exactly.
Type or paste any SMILES into the task pane input and instantly see:
- 2D structure preview
- Full property table with Lipinski pass/fail indicators for each descriptor
Excel (Office JS add-in)
│
├── Custom Functions (CHEM.*) ─┐
├── Ribbon Buttons ├──► FastAPI server (localhost:8000)
└── Task Pane UI ─┘ │
RDKit (Python)
The server runs entirely locally — no data leaves your machine.
Requirements: Microsoft Excel for Mac (Microsoft 365 or standalone 2019+)
- Download
ChemToolsInstaller.dmgfrom the Releases page - Open the DMG and double-click Install ChemTools.command
- When prompted "Launch ChemTools now?" press Y
- Excel opens with ChemTools loaded in the ribbon
On subsequent launches, open ChemTools.app from ~/Applications/ — it starts the server and registers the add-in automatically.
Reinstalling / updating: run the installer again. It replaces the previous version.
Requirements: Microsoft Excel for Windows (Microsoft 365 or standalone 2019+)
- Download
ChemToolsSetup.exefrom the Releases page - Run the installer — it requires no administrator privileges
- Follow the wizard; choose whether to auto-start the server with Windows
- Excel opens with ChemTools loaded in the ribbon
The server runs silently in the background. If you need to restart it manually, run:
%LOCALAPPDATA%\ChemTools\chemtools-server\chemtools-server.exe
Requirements: Python 3.8+, conda (cadd environment with RDKit), Node.js 16+
# 1. Clone the repository
git clone https://github.com/suneelbvs/rdKit-for-Excel.git
cd Excel_plugin
# 2. Install frontend dependencies
npm install
# 3. Start the Python server
cd server
conda activate cadd
pip install -r requirements.txt
uvicorn server:app --reload --port 8000
# 4. Start the webpack dev server (separate terminal)
cd ..
npm run dev
# Serves the add-in at https://localhost:3000
# 5. Sideload the add-in in Excel
# Excel → Insert → Add-ins → Upload My Add-in → select manifest.xmlmacOS:
# Prerequisites: conda (cadd env with pyinstaller), npm
bash packaging/build.sh
# Output: release/ChemToolsInstaller.dmgWindows (must be run on a Windows machine):
See the full step-by-step guide: packaging/windows/WINDOWS_BUILD_INSTRUCTIONS.md
Quick summary:
REM 1. Install prerequisites: Miniconda, Node.js, Inno Setup 6
REM https://docs.conda.io/en/latest/miniconda.html
REM https://nodejs.org
REM https://jrsoftware.org/isdl.php
REM 2. Create Python environment
conda create -n cadd python=3.11 -y
conda activate cadd
conda install -c conda-forge rdkit -y
pip install fastapi uvicorn[standard] pillow starlette python-multipart pyinstaller
REM 3. Install Node dependencies (from project root)
npm install
REM 4. Run the build
packaging\windows\build.bat
REM Output: release\windows\ChemToolsSetup.exe
REM (falls back to ChemToolsSetup.zip if Inno Setup is not installed)Excel_plugin/
├── manifest.xml ← Office add-in manifest (SharedRuntime)
├── webpack.config.js
├── package.json
│
├── src/
│ ├── config.js ← API base URL, image dimensions
│ ├── api/chem.js ← All fetch calls to the Python server
│ ├── functions/
│ │ ├── functions.js ← CHEM.* custom formula handlers
│ │ ├── functions.json ← Formula metadata (name, params, return type)
│ │ └── functions.html ← Custom functions runtime host page
│ ├── commands/
│ │ └── commands.js ← Ribbon button handlers (ExecuteFunction)
│ └── taskpane/
│ ├── taskpane.html
│ ├── taskpane.css
│ └── taskpane.js ← Task pane UI logic
│
├── server/
│ ├── server.py ← FastAPI + RDKit endpoints
│ ├── server_main.py ← Uvicorn entry point (used by PyInstaller)
│ ├── requirements.txt
│ ├── start_server.sh ← macOS/Linux dev launcher
│ └── start_server.bat ← Windows dev launcher
│
├── packaging/
│ ├── build.sh ← macOS full build pipeline
│ ├── chemtools.spec ← PyInstaller spec (macOS)
│ ├── launcher.sh ← macOS .app launcher script
│ ├── install.sh ← macOS end-user installer
│ ├── Info.plist ← macOS .app metadata
│ ├── hooks/ ← PyInstaller hooks (RDKit, uvicorn, etc.)
│ └── windows/
│ ├── build.bat ← Windows full build pipeline
│ ├── chemtools_windows.spec ← PyInstaller spec (Windows)
│ ├── chemtools_setup.iss ← Inno Setup script → ChemToolsSetup.exe
│ └── install.bat ← Windows end-user installer (fallback)
│
├── dist/ ← Webpack build output (served by FastAPI)
├── release/ ← Final distributables (.dmg, .exe)
└── assets/
The local server exposes these REST endpoints (all GET with ?smiles= parameter):
| Endpoint | Returns |
|---|---|
GET / |
Health check |
GET /properties |
All descriptors in one call |
GET /mw |
Molecular weight |
GET /logp |
LogP |
GET /tpsa |
TPSA |
GET /hbd |
H-bond donors |
GET /hba |
H-bond acceptors |
GET /lipinski |
Ro5 pass/fail + violation count |
GET /qed |
QED score |
GET /scaffold |
Murcko scaffold SMILES |
GET /structure |
Base64-encoded PNG (width/height params) |
| Molecule | SMILES |
|---|---|
| Aspirin | CC(=O)Oc1ccccc1C(=O)O |
| Caffeine | Cn1cnc2c1c(=O)n(c(=O)n2C)C |
| Ibuprofen | CC(C)Cc1ccc(cc1)C(C)C(=O)O |
| Paracetamol | CC(=O)Nc1ccc(O)cc1 |
| Metformin | CN(C)C(=N)NC(=N)N |
| Component | Version |
|---|---|
| Python | 3.8+ |
| RDKit | 2022.09+ |
| FastAPI | 0.95+ |
| Uvicorn | 0.20+ |
| Node.js | 16+ |
| Microsoft Excel | 2019+ / Microsoft 365 |
- Substructure search across a column
- Similarity matrix / clustering
- SDF / MOL file import
- 3D conformation generation (RDKit ETKDGv3)
- Batch ADMET prediction integration
- Support for InChI / InChIKey input
- Windows auto-update mechanism
This add-in was developed by Dr Suneel Kumar BVS as part of research in computational drug discovery, with a focus on making cheminformatics accessible within everyday spreadsheet workflows used in medicinal chemistry and ADMET screening.
If you use this tool in your research, please consider citing or acknowledging this repository.
Contact Author: Author: Dr Suneel Kumar BVS — suneelkumar.bvs@gmail.com
Contributions, bug reports, and feature requests are very welcome.
- Bug / issue → Open an issue
- Feature idea → Start a discussion
- Pull request → Fork the repo, make changes, open a PR against
main
Please keep PRs focused — one feature or fix per PR.
MIT License — see LICENSE for details.
Built with RDKit, FastAPI, and the Office JS API.