Psi4 single point energy

Purpose

Provide a minimal, runnable Psi4 starter that computes one deterministic single-point energy for a bundled water geometry and records the result as compact JSON.

When to use

• You need a verified local Psi4 entry point.
• You want a tiny quantum-chemistry smoke calculation before scaling to larger molecules or better methods.
• You need a deterministic summary that can be tested in CI-like local workflows.

When not to use

• You need high-accuracy energetics, conformer searches, or production optimizations.
• You need solvent models, post-HF methods, or large basis sets.

Inputs

• Optional output JSON path
• Optional method and basis, defaulting to hf and sto-3g

Outputs

• JSON summary with Psi4 version, job label, molecule metadata, and single-point energy in Hartree

Requirements

• slurm/envs/psi4 with Psi4 installed

Procedure

1. Run slurm/envs/psi4/bin/python skills/computational-chemistry-and-molecular-simulation/psi4-single-point-energy/scripts/run_psi4_single_point.py --out skills/computational-chemistry-and-molecular-simulation/psi4-single-point-energy/assets/water_hf_sto3g_summary.json.
2. Confirm the output reports psi4_version, method, basis, and a negative energy_hartree.
3. Reuse the script as a seed for larger Psi4 workflows after validating the dedicated prefix.

Validation

• The command exits successfully under slurm/envs/psi4/bin/python.
• The result reports a 3-atom water molecule.
• The hf/sto-3g energy is reproducible for the bundled geometry.

Failure modes and fixes

• Missing Psi4 prefix: install or reactivate slurm/envs/psi4.
• Import failure: confirm the script is run with slurm/envs/psi4/bin/python, not the base interpreter.
• Numerical drift after edits: reset the geometry, method, basis, and thread count to the bundled defaults.

Safety and limits

• Educational starter only.
• The bundled water calculation is intentionally tiny and not suitable for scientific claims by itself.

Provenance

• Psi4 documentation: https://psicode.org/psi4manual/master/index.html
• Psi4 installation guide: https://psicode.org/installs/v1.10.x/

Related skills

• openmm-system-minimization