AICCM visualization

Both Γ-CCM and χ-CCM[1] write standard visualization formats that can be opened in vibe-view, VMD, VESTA, or any cube/Molden reader. Γ-CCM visualizes states from the union-and-weight construction; χ-CCM visualizes states from the finite-character construction, evaluated on its Γ-centred character mesh. Similar file formats do not imply that the two constructions supplied the same finite Hamiltonian. This page covers what each route writes and how to inspect it.

Γ-CCM visualization

The aiccm-viz route (full orbital export)

The aiccm-viz route runs an HF SCF and writes two complete orbital sets - the canonical crystalline orbitals (COs) and the localized Wannier orbitals - plus the density:

cd aiccm-2026
python run_case.py c-diamond aiccm-viz

Outputs (written to the output directory):

file	contents	open with
<system>_canonical.qvf	Crystalline orbitals (canonical HF)	vibe-view
<system>_wannier.qvf	Localized Wannier orbitals (Pipek-Mezey)	vibe-view
<system>_density.cube	HF density on a uniform grid	VMD, VESTA
<system>_co_<i>.cube	Canonical orbital i on a grid	VMD, VESTA
<system>_wannier_<i>.cube	Wannier orbital i on a grid	VMD, VESTA
<system>.molden	All orbitals in Molden format	Molden, Jmol

The JSON result (<system>__aiccm-viz.json) records the Wannier centers and spreads, the localization objective, and the unitary-invariance density residual (must be ~1e-15).

The aiccm-properties route (density + properties .qvf)

python run_case.py c-diamond aiccm-properties

Writes:

file	contents
<system>_props_canonical.qvf	Crystalline orbitals + density + per-atom properties
<system>_props_density.cube	HF density cube

Python API

from vibeqc.periodic.ccm import CCMSystem
from vibeqc.periodic.ccm.scf import run_ccm_rhf
from vibeqc.output.formats.qvf import write_qvf

ccm = CCMSystem(system, (2, 2, 2), "sto-3g")
scf = run_ccm_rhf(ccm, method="aiccm2026dev-a")

# Write a QVF archive with the HF density and orbitals
write_qvf(
    "my_system.qvf",
    molecule=ccm.supercell,
    mo_coefficients=scf.mo_coeffs,
    mo_energies=scf.mo_energies,
    density_matrix=scf.density,
    basis_name="sto-3g",
)

The QVF format is documented in the QVF specification and consumer reference.

χ-CCM visualization

χ-CCM writes standard output formats through run_periodic_job with the usual output flags:

result = vq.run_periodic_job(
    system, basis,
    method="RHF",
    jk_method="aiccm2026dev-b",
    aiccm_lattice_extension=(2, 2, 2),
    aiccm_backend="ri",
    write_molden_file=True,
    output_qvf=True,
)

Enable write_molden_file=True and output_qvf=True on any run_periodic_job call. The output directory receives:

file	contents
<jobname>.molden	Orbitals in Molden format
<jobname>.qvf	QVF orbital archive

The aiccm2026dev_b_band_structure function also writes band-structure data that can be plotted with the standard band-structure tools (vibeqc.bands).

Two small chi-CCM-B QVF fixtures are bundled with the documentation: a 3D vacuum-padded H-chain and a 3D H2-pair, both run with the RI backend and emitted with Wannier-centre overlays. Their reproducible inputs, full .out logs, sanitized .system manifests, QVFs, and vibe-view PNG captures are in the chi-CCM-B fixture README.

These fixtures were generated at pre-D89 source d746d238 (shown as d746d23 in the archived output). They are visualization-only fixtures. Their records lack the normative D89 approach identity fields, so they are not construction-comparison or numerical-validation evidence. Open them directly with:

vibe-view open docs/_static/examples/chi-ccm-b-qvf/output-chi-ccm-b-hchain-ri-n4-wannier.qvf
vibe-view open docs/_static/examples/chi-ccm-b-qvf/output-chi-ccm-b-h2pair-3d-ri-n2-wannier.qvf

Opening a QVF in vibe-view

vibe-view is the GPU-accelerated 3-D viewer for QVF archives. From the vibe-qc checkout:

vibe-view open <path/to/file.qvf>

Or from within Python:

from vibeview.qvf import QVFReader

reader = QVFReader("c-diamond_canonical.qvf")
print(len(reader.sections), "sections")

The vibe-view handover documents the current capabilities (orbital isosurfaces, density, bond analysis, COOP/COHP).

Opening a cube file in VMD / VESTA

Cube files are plain-text volumetric grids. Any standard tool reads them:

# VMD
vmd c-diamond_density.cube

# VESTA (GUI)
open c-diamond_density.cube

For orbital cubes, VMD can display isosurfaces of individual orbitals:

# VMD Tcl console
mol new c-diamond_co_0.cube
mol addrep top
mol modstyle 0 top Isosurface 0.05 0 0 0 1 1

Rendering for publication

The QVF → vibe-view pipeline is the recommended path for paper and cover figures:

1. Run aiccm-viz on the target system

2. Open the .qvf in vibe-view

3. Choose the orbital, isovalue, and colour map

4. Export a high-resolution PNG or the camera state for reproducibility

The .cube files are the fallback when vibe-view is not available or when you need VESTA’s crystallographic rendering (bonds, polyhedra, unit-cell outline).

See also

• QVF format specification

• QVF consumer reference

• QVF writer handover

• vibe-view handover

• Orbital visualization tutorial

• Periodic orbital cubes tutorial

• vibe-view walkthrough

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[1]

Γ-CCM and χ-CCM are distinct CCM approaches. Γ-CCM uses the union-and-weight/Wigner–Seitz integral-weighting construction; χ-CCM uses the finite-translation-group character construction. They are compared at a declared common exchange-q=0 convention. Their distinction is not a choice of Coulomb kernels, and equality for a specified operator/route is evidence to establish, not a naming premise.