2026.6

Release Notes

• Added difference map calculation for cryoEM (as implemented in Servalcat)
• Added a GFN-xTB engine (xtb_manager) for quantum-mechanics restraints
• Improvements to reduce2 hydrogen placement (with a reduce1/reduce2
• Added iotbx.file_io for single-parse file reading, with xz/lzma/zstd

Checksums

SHA256

252d5d16a6e0030666a1dac681f24673e31a9903c1afca2a6a2f42db50f38da7  cctbx-2026.6.tar.gz
b838b6122eb1b64588d08b6e91da7435440af1a04460919c3efb4c4afe88fc93  chem_data-2026.6-pyhbfd0f4e_0.conda

2026.5

Release Notes

• Added qttbx PySide2 and PySide6 widgets for editing PHIL parameters with validation
• Migrated wxtbx and gltbx to wxPython 4.2 and dropped wxPython 3 support
• Added reference-model hydrogen-bond restraints and a Ramachandran target override
• Added CONST dihedral restraints and parameterization of riding hydrogens when a torsion is missing

Checksums

SHA256

93d1d115136bc2056a6c2edb849de9df199fd1990d658a9368dc542cbd88c3b1  cctbx-2026.5.tar.gz
919db74c2a241b725c5180657767f56621da6ab1b0ca0c353e1d8b7bd5048a4b  chem_data-2026.5-pyhee5eca3_0.conda

2026.4

Release Notes

• Added new xcif C++ CIF parser, selectable via engine= in iotbx.cif.reader
• Ported Niggli reduction to C++
• Improvements to ligand validation GUI

Checksums

SHA256

4bd644a11f4f048aa1508323350135adccda9e2df06f4996b0a30cb6b38e180c  cctbx-2026.4.tar.gz
c31ae436b73f391adc17568e9e9bf3622dac36e906359487f8e33d67823a83b5  chem_data-2026.4-pyhfb4f4e0_0.conda

2026.3

cctbx-2026.3.tar.gz not updated since 2025.12 #1145
cctbx-2026.3-updated.tar.gz is correct source tarball

Release Notes

• Add hydrogens that may not be uniquely defined by geometry
• Improvements to ligand validation tool
• Fix bug in adding sequence information to mmCIF files where

Checksums

SHA256

43504c71a3c01cc2fc572ecf92d56dcc09ae320026d184b57515c51213f6e40b  cctbx-2026.3-updated.tar.gz
6c58706e51d55450d236cfed531fcd37655bd1221418be4511861cb13fb9ee99  cctbx-2026.3.tar.gz
881da68228d46531cd20ae15266355ad7e44a29df2507dbd472459e508666738  chem_data-2026.3-pyhfb4f4e0_0.conda

2026.2

Not updated since 2025.12 #1145

Release Notes

• Expand support for variable resolution maps
• Improve probe2 support for RNA
• Fixed bug for Boost 1.88 support

Checksums

SHA256

984ed1bde5b8914472bfa3c0ca7856ebb58e079e04a3a1d91aac16d653344ae1  cctbx-2026.2.tar.gz
d8dd4991463112482b39b528a327aa2ded7f5f7135fc5ebae5010d422a6c48be  chem_data-2026.2-pyhfb4f4e0_0.conda

2026.1

Not updated since 2025.12 #1145

Release Notes

• Improvements to variable resolution map calculation
• Fix bug in counting atoms split across chains with the same chain ID
• Fix bug in reading MRC files with 16-bit floats

Checksums

SHA256

626fcfa4266610c4fd0e8c27195e03757023db459753b48aab7d2b93410fd416  cctbx-2026.1.tar.gz
38b9e49a56f8e51485acb1067d9a689bf1866c185faf38fc711df271692eeea2  chem_data-2026.1-pyh3b8433e_0.conda

2025.12

Release Notes

• Polder maps: stop when data is twinned
• mmtbx.table_one: fix bug with twinned data and using model header information
• Speed up variable resolution map calculation

Checksums

SHA256

4d28b0d7145fce09a997dcda6d0279e12ad622c3b0fc6fa21fbb9414b8f62fb7  cctbx-2025.12.tar.gz
47c9d6bacd4071494a6e80336e6ad22ceb35b24b7465863adebe9f02e42d88e1  chem_data-2025.12-pyhe0d8492_0.conda

2025.11

Release Notes

• Print additional information from DiSCaMB
• More developments in QM restraints

Checksums

SHA256

e72b32eab98cdb86011981e903f812dcf70bc7c102faa6a332e18e70e4021d95  cctbx-2025.11.tar.gz
b157567eeb89a7228c2aa9f9c6a4e6fa4a04250ff063d733950fa6b0d1b5e8f9  chem_data-2025.11-pyhe0d8492_0.conda

2025.10

Release Notes

• Added mmtbx.reduce_cryoem_resolution for creating lower resolution maps
• Initial support for Python 3.14
• General wxPython syntax updates in wxtbx

Checksums

SHA256

ee9e6d179d8823f72b66c1eb8b4e49378de3d596dba4e3efdb982ebf51d3e241  cctbx-2025.10.tar.gz
97206e13912ea8a91bc989b29b1d1b5815dd222d2a8cdf300336c1cfd66191e3  chem_data-2025.10-pyhe0d8492_0.conda

2025.9

Release Notes

• Added tool for finding restraint files in installation
• Improvements to variable resolution map calculation

Checksums

SHA256

82150d9f60ee59ab3b9f788a661abef03c86a2c02a87666c9a84b684d7c5e135  cctbx-2025.9.tar.gz
daaaae61bcd7e437eea0192e4aecf96d6717b4d276189541c5217d9690847f35  chem_data-2025.9-pyhe0d8492_0.conda