Portable geometry and optional ORCA inputs

The main calculation walkthrough uses vibe-qc. This page covers the remaining writers with the same lactic-acid-3d.vsk starting geometry. No ORCA installation is needed to write an input. Running it requires your separately installed ORCA program.

Write XYZ and QCSchema

vibe-sketcher input lactic-acid-3d.vsk --species m1 --program xyz --output-dir xyz
vibe-sketcher input lactic-acid-3d.vsk --species m1 --program qcschema-molecule --output-dir molecule
vibe-sketcher input lactic-acid-3d.vsk --species m1 --program qcschema \
  --task sp --method HF --basis def2-SVP --output-dir energy
vibe-sketcher input lactic-acid-3d.vsk --species m1 --program qcschema \
  --task freq --method HF --basis def2-SVP --output-dir hessian

XYZ uses angstrom and records charge/multiplicity in the comment. The QCSchema molecule uses schema version 2 and bohr. The QCSchema input uses schema version 1, an energy or HF hessian driver, and empty keywords. Check units before reading coordinates in another program: QCSchema geometry is a flat list of 3 * number_of_atoms values, not one coordinate row per atom. These writers use the first conformer. The units reference compares the generated representations.

The shared source geometry. The generated XYZ and JSON are in the example archive.

XYZ and qcschema-molecule are geometry-only and refuse a calculation spec. QCSchema refuses optimisation, TDDFT, NMR and unsupported keyword fields; it does not translate them into an unrelated driver. The generator writes both geometry formats, both QCSchema tasks and checked refusal examples.

Write and inspect an ORCA input

In Inputs, select ORCA, B3LYP/def2-SVP, and NMR. Write inputs produces an .inp file. This screenshot deliberately shows the optional ORCA workflow; the other calculation tutorials use vibe-qc.

A generated ORCA NMR input, not an executed ORCA calculation.

The archive contains examples for all six ORCA tasks: sp, opt, freq, opt+freq, tddft and nmr. inputs/orca/options/spec.json adds D3BJ, def2-TZVP, def2/J, RIJCOSX, SMD water, two processes, 1000 MB per core and a frozen position. Run this from the generated or unpacked directory containing lactic-acid-3d.vsk and inputs/. The POSIX shell substitution passes the JSON contents to --spec, which does not accept a filename:

vibe-sketcher input lactic-acid-3d.vsk --species m1 --program orca \
  --spec "$(cat inputs/orca/options/spec.json)" --output-dir orca-options

Inspect the keyword line, %pal, %maxcore, solvation/TDDFT/constraint blocks and the * xyz charge multiplicity geometry. ORCA constraints can also specify distances, angles and dihedrals through JSON, with zero-based atom indices; inputs/orca/internal-constraints/ exercises all three. A missing constraint value uses its starting value; a position constraint has no value.

Consult the exact option table before changing methods. Composite methods carry their own basis/approximations. RI-MP2 and DLPNO need appropriate correlation-fitting bases. Some method/task combinations, duplicate dispersion choices and missing auxiliary bases are refused. These checks deliberately prevent unsupported inputs from being guessed.