Gaussian LSP

Language Server Protocol implementation for Gaussian quantum chemistry software.

Features

• Auto-completion for Gaussian keywords (methods, basis sets, job types)
• Diagnostics with error and warning detection
• Hover documentation for Gaussian keywords
• Code formatting for consistent file structure
• Support for .gjf and .com input files
• Full periodic table support (118 elements)
• ModRedundant input support
• ONIOM layer specification support

Installation

pip install gaussian-lsp

Usage

Start the language server:

gaussian-lsp

Editor Integration

This package provides the language server executable. To use it in an editor, connect an LSP client to the gaussian-lsp command and register .gjf and .com files as Gaussian input files. The repository does not currently ship a VS Code extension or TextMate grammar.

Syntax highlighting depends on your editor or extension setup.

OpenQC Alignment

This repository is part of the newtontech computational chemistry LSP family. newtontech/OpenQC-VSCode is the VS Code-facing integration layer for this server.

When changing diagnostics, completions, hover text, file detection, or parser fixtures, also update or open an alignment issue in OpenQC-VSCode so the extension behavior stays consistent with gaussian-lsp.

Supported File Extensions

• .gjf - Gaussian input file
• .com - Gaussian command file

Development

git clone https://github.com/newtontech/gaussian-lsp.git
cd gaussian-lsp
pip install -e ".[dev]"

Running Tests

pip install -e ".[dev]"
python -m pytest
npm ci
npm run test:ts

The TypeScript parser under src/parsers is active and covered by npm run typecheck plus npm run test:ts:coverage in CI.

If your local Python environment is not set up yet, you can reproduce the Python suite without modifying the project environment:

uv run --with pytest --with pytest-asyncio --with pytest-cov python -m pytest

Code Quality

black src/ tests/
isort src/ tests/
mypy src/
flake8 src/ tests/
pre-commit run --all-files

See docs/pr-review-workflow.md for the merge/modify/hold PR review process and the parallel Codex subagent review lanes.

Supported Keywords

Methods

• Hartree-Fock: HF, RHF, UHF, ROHF
• DFT: B3LYP, PBE, PBE0, M06, M062X, wB97XD, etc.
• Post-HF: MP2, MP3, MP4, CCSD, CCSD(T)
• Semi-empirical: PM3, PM6, PM7, AM1

Basis Sets

• Pople: 6-31G, 6-31G(d), 6-311G(d,p), etc.
• Dunning: cc-pVDZ, cc-pVTZ, cc-pVQZ
• Karlsruhe: def2-SVP, def2-TZVP, def2-QZVP
• Pseudopotentials: LANL2DZ, SDD

Job Types

• SP - Single point
• OPT - Geometry optimization
• FREQ - Frequency calculation
• OPT FREQ - Optimization + frequency
• TS - Transition state search
• IRC - Reaction coordinate
• NMR - NMR chemical shifts
• TD - Time-dependent DFT

Example Input File

%chk=water.chk
%mem=2GB
%nproc=4

# B3LYP/6-31G(d) opt freq

Water molecule optimization

0 1
O  0.000000  0.000000  0.000000
H  0.757160  0.586260  0.000000
H -0.757160  0.586260  0.000000

License

MIT

Changelog

See LICENSE for the license text and CHANGELOG.md for version history.