User guide

Reference-style background: each page describes a single concept / API area in depth. Read the tutorials first if you’re new to vibe-qc.

Molecular methods

• Molecules
• Basis sets
• Molecular basis-set optimisation
• Cohesive energies and the energy-engine abstraction
• Molecular naming
• Functionals
• ROHF and ROKS (restricted open-shell SCF)
• MP2 and double hybrids
• CC2, CC3, CCSD, CCSDT, QCISD, and perturbative triples
• DLPNO methods (MP2, CCSD, CCSD(T))
• Non-mean-field solvers (vibeqc.solvers)
• Composite “3c” methods
• Machine-learning interatomic potentials (MACE)
• Semiempirical Methods
• Semiempirical and MACE method comparison
• MSINDO (semiempirical INDO)
• DFT+U (Hubbard correction)
• Effective core potentials (ECPs)

Periodic methods

• Periodic systems
• Crystal lattices
• Slabs and adsorbates
• Green’s-function surface embedding
• k-point meshes
• Multi-k periodic SCF
• Ewald summation in periodic systems
• BIPOLE: Ewald-J-split periodic HF and DFT
• Plane-wave Hartree-J via GPW / GAPW
• Periodic-SCF methods: BIPOLE, GDF, GPW / GAPW
• Periodic JK routes, method-family parity policy
• The cyclic cluster model (CCM)
• χ-CCM / aiccm2026dev-b (experimental)
• AICCM - Γ-CCM, the aiccm2026dev-a line (experimental)
• χ-CCM / aiccm2026dev-b: an independent finite-torus derivation
• χ-CCM / aiccm2026dev-b decisions and open questions
• COOP/COHP: bonding analysis for periodic systems

SCF & convergence

• SCF convergence
• SCF Fock-build modes
• Eigensolver & SCF Solver Framework
• Initial guesses
• Smearing (fractional occupations for periodic SCF)
• Metallic BZ integration: the Gilat-Raubenheimer net
• Linear dependence and screening in periodic SCF
• Density fitting (RIJ / RIJK / RIJCOSX)
• Implicit solvation (CPCM / COSMO)
• Settings introspection
• Memory budget

Workflows & properties

• Relaxed coordinate scans
• Nudged Elastic Band (NEB)
• Molecular dynamics
• Post-SCF properties
• Bond analysis: Wiberg, NBO, EDA, IBOs, and orbital entanglement
• Band structure and density of states
• Volumetric data: cube, XSF, and BXSF files
• The data_library/ parameter-storage standard
• Experimental reference data (vqfetch reference)
• QTAIM: topological analysis of the electron density

Import & export

• ASE integration
• External QC codes (ORCA / Psi4 / others)
• External structures (vqfetch)
• Moving from PySCF
• Moving from CRYSTAL
• Moving from ORCA
• Moving from Gaussian
• Input scripts and output files
• The output logger (vibeqc.output)
• Automatic citations

Tooling

• BLAS + LAPACK backend
• The vq calculation queue
• Running vibe-qc from Jupyter Lab
• Keyword index
• Basis-set toolkit

Looking for vibe-view or QVF?

The viewer and format reference pages (interactive viewer, terminal mode, desktop app, vq Job Manager, live reload, QVF job containers) are grouped with their tutorials and the format toolkit under QVF and vibe-view.