OpenQP Manual

Manual version: 1.2.0; OpenQP version: 1.2.0

Open Quantum Platform (OpenQP) is a quantum chemistry package centered on HF/DFT, MP2, TDHF/TDDFT, SF-TDDFT, MRSF-TDDFT, and related workflows for multiconfigurational ground and excited states. The manual is organized around what users usually need first: install OpenQP, prepare an input, run a calculation, then look up keywords when a workflow needs more control. The lower-level API reference is intentionally placed last, after workflows and keywords.

Start Here

• Installation: package install, source build, BLAS/LAPACK, OpenMP, MPI, and runtime-file layout.
• Build Options: complete CMake options, package-build overrides, BLAS/LAPACK choices, and external dependency cache behavior.
• Quickstart: the shortest path from a molecule to an OpenQP output file.
• .oqp input: the recommended input style used first throughout the workflow chapters.
• Run OpenQP from Python: the second, programmatic style for scripts, notebooks, and workflow managers.
• Legacy .inp input: the supported sectioned format for existing decks and legacy-only controls.
• Examples: runnable inputs stored in the OpenQP code repository.
• References: platform, MP2, MRSF-TDDFT, SOC, scalar relativistic, and PCM/ddX papers cited by the manual.

Common Workflows

• Ground-state HF and DFT
• Energy-only MP2 and spin-scaled MP2 variants
• TDDFT and TDHF energies and gradients
• SF-TDDFT spin-flip energies and gradients
• MRSF-TDDFT energies and gradients
• Hessian and frequencies
• Geometry optimization
• Spin-orbit coupling and scalar relativistic DKH correction
• NACME
• Energy-only PCM/ddX
• MRSF-EKT ionization potentials and electron affinities
• NMR, IR, and Raman

Keyword Reference

The keyword reference is the code-aligned lookup layer for high-drift input sections such as [input], [scf], [optimize], [oqp], [mp2], [pcm], and [symmetry]. It should be checked against pyoqp/oqp/molecule/oqpdata.py and pyoqp/oqp/utils/input_checker.py when OpenQP changes.

API Documentation

Workflow pages use the same order throughout the manual: recommended .oqp, Python, then legacy .inp. The Run OpenQP from Python chapter expands the script-based form. The API chapter appears last in the manual and is the lower-level reference for oqp.pyoqp.Runner, in-memory inputs, result extraction through runner.mol, and the input-checking API used by front ends and automated workflows.

Web Tools

• OpenQP Web prepares inputs in the browser and previews structures locally.
• OpenQP Input Generator provides a browser-based input builder.
• OpenqpView inspects OpenQP logs, JSON, Molden, cube, and XYZ data in the browser.