XTB MCP Server

MCP server that generates and validates input files for xtb, the Grimme-group extended tight-binding code, so Claude can set up semi-empirical quantum-chemistry calculations without you hand-writing control decks.

   
Type MCP server
Supplier PhelanShao (community OSS)
Availability Beta — install from a clone; not published to PyPI
Pricing Free / OSS (MIT)
Capabilities Read/Write — writes input files and control decks to disk

Clone and install:

git clone https://github.com/PhelanShao/xtb-mcp-server
cd xtb-mcp-server
pip install -r requirements.txt
python run_tests.py   # optional: confirms the install; not a long-lived server

Register with Claude Code (replace /path/to/xtb-mcp-server with the absolute path of your clone — e.g., /Users/you/repos/xtb-mcp-server, or $(pwd) if you are still inside it from the previous step):

claude mcp add --transport stdio xtb -- python /path/to/xtb-mcp-server/main.py

For Claude Desktop, add to claude_desktop_config.json (this is the snippet the upstream README shows, with the placeholder path made explicit):

{
  "mcpServers": {
    "xtb-mcp-server": {
      "command": "python",
      "args": ["/path/to/xtb-mcp-server/main.py"],
      "env": {}
    }
  }
}

Claude Code and Claude Desktop launch the process themselves over stdio — you do not keep a terminal open.

What it does

Ten tools:

  • generate_xtb_input_package — build a complete input set for a calculation type (single point, optimization, frequency, scan, MD).
  • generate_xcontrol_file — write an xcontrol deck with custom constraints and parameters.
  • validate_xtb_input_files — syntax- and parameter-check an input set before submission.
  • convert_structure_file_format — interconvert XYZ, TURBOMOLE coord, and Gaussian geometry formats.
  • explain_xtb_parameters — narrate what a given keyword or Hamiltonian choice does.
  • generate_enhanced_sampling_input — metadynamics and pathfinder sampling setups.
  • generate_wavefunction_analysis_input — orbital and population analysis runs.
  • generate_oniom_input — multi-layer QM/MM (ONIOM) partitions.
  • generate_spectroscopy_input — spectroscopic property calculations.
  • analyze_trajectory — post-process MD trajectory output.

Covers the GFN0-xTB, GFN1-xTB, GFN2-xTB, and GFN-FF Hamiltonians.

Primary use cases: Conformer optimization and frequency checks on small organics, reaction-coordinate scans, QM/MM partitioning, metadynamics setup for conformational search.

Notes

stdio transport. The server’s job is input preparation and validation — the tool names are all generate_* / validate_* / explain_*. Unverified — the README does not state whether the xtb binary itself must be installed separately to execute the generated decks (or for analyze_trajectory); assume you need xtb on PATH to actually run the calculations, and install it via conda install -c conda-forge xtb if so.

Unverified — the README states no minimum Python version.

The README’s license statement appears only in its Chinese section (“本项目采用 MIT 许可证” — this project uses the MIT License).

To actually run the calculations rather than prepare their inputs, see ChemGraph (Argonne, an MCP server that drives ASE against TBLite/xTB, NWChem, ORCA, and MACE).

Sources

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