id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
18669	Excess mmCIF bonds	Tristan Croll	Greg Couch	"{{{
The following bug report has been submitted:
Platform:        Windows-10-10.0.26100
ChimeraX Version: 1.10.1 (2025-07-24 20:15:27 UTC)
Description
I'm reviewing the manuscript for EMProt (http://huanglab.phys.hust.edu.cn/EMProt/), and the combination of its rather barebones mmCIF output (containing only the _atom_site table) and some nasty geometry issues in places has surfaced what I'd call a bug in the ChimeraX mmCIF reader. On opening I see the following warnings in the log:

Missing entity information. Treating each chain as a separate entity. Missing or incorrect sequence information. Inferred polymer connectivity.

... which is sensible, except that in the problematic regions the model comes out looking like the attached image, with every atomic clash turned into a covalent bond. If I save the model to PDB, strip out the LINK and CONECT lines and reopen, the connectivity looks normal - so at the very least, the mmCIF and PDB readers give different results for effectively the same input.

OpenGL version: 3.3.0 NVIDIA 576.57
OpenGL renderer: NVIDIA GeForce RTX 3070 Laptop GPU/PCIe/SSE2
OpenGL vendor: NVIDIA Corporation

Python: 3.11.4
Locale: en_GB.cp1252
Qt version: PyQt6 6.8.1, Qt 6.8.2
Qt runtime version: 6.8.2
Qt platform: windows

Manufacturer: HP
Model: HP ZBook Studio 15.6 inch G8 Mobile Workstation PC
OS: Microsoft Windows 11 Pro (Build 26100)
Memory: 34,007,068,672
MaxProcessMemory: 137,438,953,344
CPU: 16 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz
OSLanguage: en-GB

Installed Packages:
    alabaster: 1.0.0
    appdirs: 1.4.4
    asteval: 1.0.6
    asttokens: 3.0.0
    babel: 2.17.0
    beautifulsoup4: 4.13.3
    blockdiag: 3.0.0
    blosc2: 3.6.1
    build: 1.2.2.post1
    certifi: 2025.7.14
    cftime: 1.6.4.post1
    charset-normalizer: 3.4.2
    ChimeraX-AddCharge: 1.5.19
    ChimeraX-AddH: 2.2.7
    ChimeraX-AlignmentAlgorithms: 2.0.2
    ChimeraX-AlignmentHdrs: 3.6.1
    ChimeraX-AlignmentMatrices: 2.1
    ChimeraX-Alignments: 2.20.2
    ChimeraX-AlphaFold: 1.0.1
    ChimeraX-AltlocExplorer: 1.1.2
    ChimeraX-AmberInfo: 1.0
    ChimeraX-Aniso: 1.1.4
    ChimeraX-Arrays: 1.1
    ChimeraX-Atomic: 1.60.7
    ChimeraX-AtomicLibrary: 14.1.19
    ChimeraX-AtomSearch: 2.0.1
    ChimeraX-AxesPlanes: 2.4
    ChimeraX-BasicActions: 1.1.3
    ChimeraX-BILD: 1.0
    ChimeraX-BlastProtein: 3.0.0
    ChimeraX-Boltz: 1.0
    ChimeraX-BondRot: 2.0.4
    ChimeraX-BugReporter: 1.0.2
    ChimeraX-BuildStructure: 2.13.1
    ChimeraX-Bumps: 1.0
    ChimeraX-BundleBuilder: 1.5.1
    ChimeraX-ButtonPanel: 1.0.1
    ChimeraX-CageBuilder: 1.0.1
    ChimeraX-CellPack: 1.0
    ChimeraX-Centroids: 1.4
    ChimeraX-ChangeChains: 1.1
    ChimeraX-CheckWaters: 1.5
    ChimeraX-ChemGroup: 2.0.2
    ChimeraX-Clashes: 2.3
    ChimeraX-Clipper: 0.25.2
    ChimeraX-ColorActions: 1.0.5
    ChimeraX-ColorGlobe: 1.0
    ChimeraX-ColorKey: 1.5.8
    ChimeraX-CommandLine: 1.3
    ChimeraX-ConnectStructure: 2.0.1
    ChimeraX-Contacts: 1.0.1
    ChimeraX-Core: 1.10.1
    ChimeraX-CoreFormats: 1.2
    ChimeraX-coulombic: 1.4.5
    ChimeraX-Crosslinks: 1.0
    ChimeraX-Crystal: 1.0
    ChimeraX-CrystalContacts: 1.0.1
    ChimeraX-DataFormats: 1.2.4
    ChimeraX-Dicom: 1.2.7
    ChimeraX-DistMonitor: 1.4.2
    ChimeraX-DockPrep: 1.1.4
    ChimeraX-Dssp: 2.0
    ChimeraX-EMDB-SFF: 1.0
    ChimeraX-ESMFold: 1.0
    ChimeraX-FileHistory: 1.0.1
    ChimeraX-FunctionKey: 1.0.1
    ChimeraX-Geometry: 1.3
    ChimeraX-gltf: 1.0
    ChimeraX-Graphics: 1.4.1
    ChimeraX-Hbonds: 2.5.1
    ChimeraX-Help: 1.3
    ChimeraX-HKCage: 1.3
    ChimeraX-IHM: 1.1
    ChimeraX-ImageFormats: 1.2
    ChimeraX-IMOD: 1.0
    ChimeraX-IO: 1.0.3
    ChimeraX-ISOLDE: 1.10.1
    ChimeraX-ItemsInspection: 1.0.1
    ChimeraX-IUPAC: 1.0
    ChimeraX-KVFinder: 1.6.2
    ChimeraX-Label: 1.1.14
    ChimeraX-ListInfo: 1.2.2
    ChimeraX-Log: 1.2
    ChimeraX-LookingGlass: 1.1
    ChimeraX-Maestro: 1.9.1
    ChimeraX-Map: 1.3
    ChimeraX-MapData: 2.0
    ChimeraX-MapEraser: 1.0.1
    ChimeraX-MapFilter: 2.0.1
    ChimeraX-MapFit: 2.0
    ChimeraX-MapSeries: 2.1.1
    ChimeraX-Markers: 1.0.1
    ChimeraX-Mask: 1.0.2
    ChimeraX-MatchMaker: 2.2.2
    ChimeraX-MCopy: 1.0
    ChimeraX-MDcrds: 2.10.1
    ChimeraX-MedicalToolbar: 1.1
    ChimeraX-Meeting: 1.0.1
    ChimeraX-MLP: 1.1.1
    ChimeraX-mmCIF: 2.16
    ChimeraX-MMTF: 2.2
    ChimeraX-ModelArchive: 1.0
    ChimeraX-Modeller: 1.5.19
    ChimeraX-ModelPanel: 1.5.1
    ChimeraX-ModelSeries: 1.0.1
    ChimeraX-Mol2: 2.0.3
    ChimeraX-Mole: 1.0
    ChimeraX-Morph: 1.0.2
    ChimeraX-MouseModes: 1.2
    ChimeraX-Movie: 1.0
    ChimeraX-MutationScores: 1.0
    ChimeraX-Neuron: 1.0
    ChimeraX-Nifti: 1.2
    ChimeraX-NMRSTAR: 1.0.2
    ChimeraX-NRRD: 1.2
    ChimeraX-Nucleotides: 2.0.3
    ChimeraX-OpenCommand: 1.14.1
    ChimeraX-OrthoPick: 1.0.1
    ChimeraX-PDB: 2.7.10
    ChimeraX-PDBBio: 1.0.1
    ChimeraX-PDBLibrary: 1.0.4
    ChimeraX-PDBMatrices: 1.0
    ChimeraX-PickBlobs: 1.0.1
    ChimeraX-Positions: 1.0
    ChimeraX-PresetMgr: 1.1.3
    ChimeraX-ProfileGrids: 1.1.3
    ChimeraX-PubChem: 2.2
    ChimeraX-ReadPbonds: 1.0.1
    ChimeraX-Registration: 1.1.2
    ChimeraX-RemoteControl: 1.0
    ChimeraX-RenderByAttr: 1.6.3
    ChimeraX-RenumberResidues: 1.1
    ChimeraX-ResidueFit: 1.0.1
    ChimeraX-RestServer: 1.3.1
    ChimeraX-RNALayout: 1.0
    ChimeraX-RotamerLibMgr: 4.0
    ChimeraX-RotamerLibsDunbrack: 2.0
    ChimeraX-RotamerLibsDynameomics: 2.0
    ChimeraX-RotamerLibsRichardson: 2.0
    ChimeraX-SaveCommand: 1.5.1
    ChimeraX-SchemeMgr: 1.0
    ChimeraX-SDF: 2.0.3
    ChimeraX-Segger: 1.0
    ChimeraX-Segment: 1.0.1
    ChimeraX-Segmentations: 3.5.7
    ChimeraX-SelInspector: 1.0
    ChimeraX-SeqView: 2.17.1
    ChimeraX-Shape: 1.1
    ChimeraX-Shell: 1.0.1
    ChimeraX-Shortcuts: 1.2.1
    ChimeraX-ShowSequences: 1.0.3
    ChimeraX-SideView: 1.0.1
    ChimeraX-SimilarStructures: 1.0.1
    ChimeraX-Smiles: 2.1.2
    ChimeraX-SmoothLines: 1.0
    ChimeraX-SpaceNavigator: 1.0
    ChimeraX-StdCommands: 1.19.1
    ChimeraX-STL: 1.0.1
    ChimeraX-Storm: 1.0
    ChimeraX-StructMeasure: 1.2.1
    ChimeraX-Struts: 1.0.1
    ChimeraX-Surface: 1.0.1
    ChimeraX-SwapAA: 2.0.1
    ChimeraX-SwapRes: 2.5.2
    ChimeraX-TapeMeasure: 1.0
    ChimeraX-TaskManager: 1.0
    ChimeraX-Test: 1.0
    ChimeraX-Toolbar: 1.2.3
    ChimeraX-ToolshedUtils: 1.2.4
    ChimeraX-Topography: 1.0
    ChimeraX-ToQuest: 1.0
    ChimeraX-Tug: 1.0.1
    ChimeraX-UI: 1.45.2
    ChimeraX-Umap: 1.0
    ChimeraX-uniprot: 2.3.1
    ChimeraX-UnitCell: 1.0.1
    ChimeraX-ViewDockX: 1.4.4
    ChimeraX-VIPERdb: 1.0
    ChimeraX-Vive: 1.1
    ChimeraX-VolumeMenu: 1.0.1
    ChimeraX-vrml: 1.0
    ChimeraX-VTK: 1.0
    ChimeraX-WavefrontOBJ: 1.0
    ChimeraX-WebCam: 1.0.2
    ChimeraX-WebServices: 1.1.5
    ChimeraX-Zone: 1.0.1
    colorama: 0.4.6
    comm: 0.2.2
    comtypes: 1.4.10
    contourpy: 1.3.2
    coverage: 7.10.0
    cxservices: 1.2.3
    cycler: 0.12.1
    Cython: 3.0.12
    debugpy: 1.8.15
    decorator: 5.2.1
    dill: 0.4.0
    docutils: 0.21.2
    executing: 2.2.0
    filelock: 3.18.0
    fonttools: 4.59.0
    funcparserlib: 2.0.0a0
    glfw: 2.9.0
    grako: 3.16.5
    h5py: 3.14.0
    html2text: 2024.2.26
    idna: 3.10
    ihm: 2.2
    imagecodecs: 2024.6.1
    imagesize: 1.4.1
    iniconfig: 2.1.0
    ipykernel: 6.29.5
    ipython: 8.26.0
    ipywidgets: 8.1.7
    jedi: 0.19.1
    Jinja2: 3.1.6
    jupyter_client: 8.6.3
    jupyter_core: 5.8.1
    jupyterlab_widgets: 3.0.15
    kiwisolver: 1.4.8
    line_profiler: 4.2.0
    lmfit: 1.3.4
    lxml: 5.3.1
    lz4: 4.3.2
    MarkupSafe: 3.0.2
    matplotlib: 3.10.1
    matplotlib-inline: 0.1.7
    msgpack: 1.1.0
    ndindex: 1.10.0
    nest-asyncio: 1.6.0
    netCDF4: 1.6.5
    networkx: 3.3
    nibabel: 5.2.0
    nptyping: 2.5.0
    numdifftools: 0.9.41
    numexpr: 2.11.0
    numpy: 1.26.4
    nvidia-nvjitlink-cu12: 12.9.86
    OpenMM: 8.2.0
    OpenMM-CUDA-12: 8.2.0
    openvr: 1.26.701
    packaging: 24.2
    pandas: 2.3.1
    ParmEd: 4.2.2
    parso: 0.8.4
    pep517: 0.13.1
    pickleshare: 0.7.5
    pillow: 10.4.0
    pip: 25.0.1
    pkginfo: 1.11.1
    platformdirs: 4.3.8
    pluggy: 1.6.0
    prompt_toolkit: 3.0.51
    psutil: 7.0.0
    pure_eval: 0.2.3
    py-cpuinfo: 9.0.0
    pycollada: 0.8
    pydicom: 2.4.4
    Pygments: 2.18.0
    pynmrstar: 3.3.5
    pynrrd: 1.0.0
    PyOpenGL: 3.1.9
    PyOpenGL-accelerate: 3.1.9
    pyopenxr: 1.1.4501
    pyparsing: 3.2.3
    pyproject_hooks: 1.2.0
    PyQt6-commercial: 6.8.1
    PyQt6-Qt6: 6.8.2
    PyQt6-WebEngine-commercial: 6.8.0
    PyQt6-WebEngine-Qt6: 6.8.2
    PyQt6_sip: 13.10.0
    pytest: 8.4.1
    pytest-cov: 6.2.1
    python-dateutil: 2.9.0.post0
    pytz: 2025.2
    pywin32: 310
    pyzmq: 27.0.0
    qtconsole: 5.5.2
    QtPy: 2.4.3
    qtshim: 1.1
    RandomWords: 0.4.0
    requests: 2.32.3
    roman-numerals-py: 3.1.0
    scipy: 1.14.0
    setuptools: 78.1.0
    sfftk-rw: 0.8.1
    six: 1.16.0
    snowballstemmer: 3.0.1
    sortedcontainers: 2.4.0
    soupsieve: 2.7
    Sphinx: 8.2.3
    sphinx-autodoc-typehints: 3.1.0
    sphinxcontrib-applehelp: 2.0.0
    sphinxcontrib-blockdiag: 3.0.0
    sphinxcontrib-devhelp: 2.0.0
    sphinxcontrib-htmlhelp: 2.1.0
    sphinxcontrib-jsmath: 1.0.1
    sphinxcontrib-qthelp: 2.0.0
    sphinxcontrib-serializinghtml: 2.0.0
    stack-data: 0.6.3
    superqt: 0.7.1
    tables: 3.10.2
    tcia_utils: 1.5.1
    tifffile: 2025.3.13
    tinyarray: 1.2.4
    tornado: 6.5.1
    traitlets: 5.14.3
    typing_extensions: 4.14.1
    tzdata: 2025.2
    uncertainties: 3.2.3
    urllib3: 2.5.0
    wcwidth: 0.2.13
    webcolors: 24.11.1
    wheel: 0.45.1
    wheel-filename: 1.4.2
    widgetsnbextension: 4.0.14
    WMI: 1.5.1
File attachment: bad_connectivity.jpg
}}}

[attachment:""bad_connectivity.jpg""]
"	defect	closed	normal		Input/Output		nonchimerax		Eric Pettersen				all	ChimeraX