DFTune

A VS Code extension for setting up DFT calculations by physical intent (calculation type, functional, magnetism, smearing, accuracy, DFT+U) instead of remembering tags and magic numbers. It currently supports VASP INCAR files (builder, checks, formatting) and KPOINTS files (checks, formatting); Quantum ESPRESSO is planned.

It is built for the usual HPC workflow: VS Code connected to a cluster with Remote-SSH. The extension runs on the cluster (extensionKind: workspace) and edits the INCAR in place, so no files are copied back and forth. The builder UI is bundled locally and needs no internet access.

Features

• INCAR Builder (open an INCAR, then click the gear in the editor title bar or run VASP: Open INCAR Builder)
  • Setup cards: pick "Relax ions + cell", "Phonons (finite differences)", "HSE06", "Spin-polarized"… and see which tags that writes. Calculation types: single point, relaxations, DOS/bands, phonons (finite differences or DFPT), elastic constants, dielectric tensor, optics, MD (NVT/NpT) and MLFF training/production. The current INCAR is read back into these choices; anything that doesn't fit a preset shows up as Custom and is never overwritten silently.
  • All tags: about 100 common tags with typed fields, defaults, units, descriptions and VASP wiki links. Every other tag is kept and remains editable as raw text, with its description from the VASP wiki.
  • DFT+U table per species, read from the neighbouring POSCAR.
  • Live checks (see below).
• The INCAR text stays the source of truth. The builder applies minimal text edits, so comments, alignment, tag order and unknown tags survive. Undo/redo, git diffs and the plain text editor all stay in sync, and typing in the text updates the builder.
• Plain-text support for people who prefer the editor: syntax highlighting, hover docs, completion of tags and values, and diagnostics in the Problems panel.
• Format Document (Alt+Shift+F) tidies an INCAR, e.g. one written by pymatgen: one statement per line, tag names in upper case, tags grouped by category under # Category headers, = signs and trailing comments aligned, and logical values spelled one way (.TRUE./.FALSE. or T/F). Other values and all comments are kept exactly; hand-written section headings on the same topic replace the default headers. It refuses to run while the file has syntax problems. Each step can be switched off in the settings (dftune.format.*).
• KPOINTS files (KPOINTS, KPOINTS.*, KPOINTS_*, *.kpoints) get syntax highlighting, checks in the Problems panel and Format Document. The checks read the file the way VASP does, by line position, and flag what it cannot read: a missing or non-numeric count, subdivisions or coordinates, a file that ends before the announced k points, line-mode points that don't come in pairs, tetrahedron corners outside the k-point list. Softer notes: an even Monkhorst–Pack mesh (no Γ), a mode word VASP reads as generating vectors, all-zero weights, text VASP ignores. Format Document only changes whitespace: mode words get one spelling (gamma → Gamma), k points and vectors are lined up on the decimal point with their labels in one column, and line-mode segments are separated by one blank line. Numbers are copied as written, and it refuses to run while the file has errors.
• New VASP Calculation… (right-click a folder): answer a few quick picks and get a commented INCAR.

Checks

Typos (ENCTU → did you mean ENCUT?), tags VASP doesn't know (it silently ignores them), deprecated and renamed tags, invalid values, duplicates, and physics/setup pitfalls such as: NSW > 0 without IBRION (silently runs MD), MD without POTIM/TEBEG, tetrahedron smearing with forces, Methfessel–Paxton by default, Pulay stress in cell relaxations, meta-GGA without LASPH, hybrid parameters without LHFCALC, MAGMOM length vs. atom count (×3 if noncollinear), per-species arrays (LDAUU, LANGEVIN_GAMMA) vs. POSCAR species, LMAXMIX for d/f +U, ICHARG = 11 with ionic steps, NCORE and NPAR both set, and LREAL for large cells.

With a KPOINTS file it also checks: KSPACING ignored because KPOINTS exists, no KPOINTS and no KSPACING (default mesh), line-mode KPOINTS without ICHARG = 11, and tetrahedron smearing with a Monkhorst–Pack mesh or fewer than 4 k points.

POSCAR and KPOINTS are found next to the INCAR (POSCAR.relax for INCAR.relax, otherwise POSCAR; likewise for KPOINTS).

Known tags are the ~600 INCAR tags on the VASP wiki (including numbered families such as LIBXC1_Pn and grouped tags such as KERNEL_TRUNCATION/LTRUNCATE), their wiki redirects (older names such as ML_FF_*), and the tags of the VTST and VASPsol patches.

Development

npm install
npm test            # unit tests for the parser, intents and validation (vitest)
npm run build       # bundle to dist/
npm run package     # build a .vsix

• F5 in VS Code launches an Extension Development Host with test/fixtures open.
• node test/harness/serve.mjs serves the builder webview in a normal browser at http://localhost:5173/test/harness/, with the fixture INCAR standing in for VS Code. Add ?incar=INCAR.mlff_train to load another fixture.

Layout

Tag defaults follow the VASP wiki for VASP 6. To add a tag, add a TagDef to src/core/tags/definitions.ts. The full tag list in src/core/tags/wikiTags.generated.ts is refreshed with node scripts/fetch-wiki-tags.mjs. Patch tags (VTST, VASPsol) live in src/core/tags/known.ts. To add a preset, add a choice to src/core/intents/definitions.ts; the tests check automatically that every choice is detected again after it is applied.

Installing

In a VS Code window connected to the cluster over Remote-SSH, search for DFTune in the Extensions view and click Install in SSH: …, or install it from the Marketplace. VS Code installs it on the remote host and keeps it up to date.

Without Marketplace access, download the .vsix from the latest release (or build it with npm run package) and run Extensions: Install from VSIX… in the remote window.

Releases are published by pushing a vX.Y.Z tag that matches package.json: CI attaches the .vsix to a GitHub Release and publishes it to the Marketplace with Trusted Publishing.

License

MIT, see LICENSE. The exception is the tag descriptions in src/core/tags/wikiTags.generated.ts: they are excerpts from the VASP Wiki, © VASP Software GmbH and the VASP Wiki authors, and are distributed under the GNU Free Documentation License 1.2.