cctbx/cctbx_project
Oct 2024 – May 2026
18 Months active
Languages Used
PythonC++PDB
Technical Skills
CrystallographyData VisualizationPythonScientific ComputingTestingBug Fix
dcliebschner
PROFILE
Dcliebschner
Over 18 months, contributed to the cctbx_project by developing and refining scientific computing tools for crystallography, ligand validation, and molecular modeling. Delivered 71 features and fixed 15 bugs, focusing on robust validation workflows, regression testing, and data analysis pipelines. Leveraged Python and C++ (via CCTBX and Python bindings) to implement command-line tools, test automation, and visualization enhancements. Improved model accuracy through advanced geometry processing, hydrogen placement, and quantum mechanical refinement integration. Enhanced reliability by expanding test coverage, optimizing data management, and addressing edge cases. The work emphasized clean code, maintainability, and reproducibility, supporting high-quality structural biology research and analysis.
Overall Statistics
Feature vs Bugs
83%Features
Repository Contributions
204Total
Bugs
15
Commits
204
Features
71
Lines of code
22,097
Activity Months18
Your Network
90 peopleShared Repositories
25
Aaron S. BrewsterMember
Billy K. PoonMember
chrissciwilliamsMember
cschlickMember
Dan DeesMember
Derek MendezMember
David Mittan-MoreauMember
David MoreauMember
David MoreauMember
Work History
May 2026
7 Commits • 1 Features
May 1, 2026May 2026: Key feature delivery and reliability improvements for cctbx/cctbx_project. Delivered constant dihedral proxies and enhanced hydrogen parameterization, expanded test coverage, and fixed logging in restraint conflict reporting. Improvements enhance dihedral handling, hydrogen placement accuracy, and the reliability of restraints reporting, driving higher modeling accuracy and lower regression risk for downstream workflows.
7 Commits • 1 Features
May 1, 2026May 2026: Key feature delivery and reliability improvements for cctbx/cctbx_project. Delivered constant dihedral proxies and enhanced hydrogen parameterization, expanded test coverage, and fixed logging in restraint conflict reporting. Improvements enhance dihedral handling, hydrogen placement accuracy, and the reliability of restraints reporting, driving higher modeling accuracy and lower regression risk for downstream workflows.
May 2026
April 2026
16 Commits • 4 Features
Apr 1, 2026April 2026 focused on reliability, validation, and usability across the cctbx_project repo. Key features delivered include deterministic regression testing improvements (seeding and removal of randomness, cleaned outputs, regression test script to compare methods, and improved test documentation/naming); reintroduction and extension of the model_vs_sequence CLI and its dedicated validation test suite to verify sequence consistency against PDB models; Ligand Validation GUI enhancements with expanded parameters, robust file handling, picklable data transfer, PNG export of fragmented ligands, CC-value annotation and coloring of fragments, and optimizations for large ligands; and metal-aware fragmentation to exclude bonds involving metal atoms from rotation to preserve rigid metal-oxo components, backed by new tests.
April 2026
16 Commits • 4 Features
Apr 1, 2026April 2026 focused on reliability, validation, and usability across the cctbx_project repo. Key features delivered include deterministic regression testing improvements (seeding and removal of randomness, cleaned outputs, regression test script to compare methods, and improved test documentation/naming); reintroduction and extension of the model_vs_sequence CLI and its dedicated validation test suite to verify sequence consistency against PDB models; Ligand Validation GUI enhancements with expanded parameters, robust file handling, picklable data transfer, PNG export of fragmented ligands, CC-value annotation and coloring of fragments, and optimizations for large ligands; and metal-aware fragmentation to exclude bonds involving metal atoms from rotation to preserve rigid metal-oxo components, backed by new tests.
March 2026
34 Commits • 13 Features
Mar 1, 2026March 2026 performance summary for cctbx/cctbx_project focused on expanding testing infrastructure, stabilizing ligand validation, and improving code quality. The work delivered concrete, developer-facing features and fixes that shorten feedback cycles, increase reliability, and strengthen scientific results validation across the repository.
34 Commits • 13 Features
Mar 1, 2026March 2026 performance summary for cctbx/cctbx_project focused on expanding testing infrastructure, stabilizing ligand validation, and improving code quality. The work delivered concrete, developer-facing features and fixes that shorten feedback cycles, increase reliability, and strengthen scientific results validation across the repository.
March 2026
February 2026
25 Commits • 7 Features
Feb 1, 2026February 2026 monthly summary for cctbx_project: Delivered substantial ligand-focused improvements, fragmentation framework enhancements, stability fixes, and codebase modernization. This work improves data quality, validation reliability, and developer velocity, enabling safer releases and faster iteration. Highlights include real-space map-enabled ligand validation, expanded fragmentation testing across RDKit/BNL/STI/HEX, a Polder resolution_factor bugfix, ongoing refactor with new tests, and CIF-format handling for ligands.
February 2026
25 Commits • 7 Features
Feb 1, 2026February 2026 monthly summary for cctbx_project: Delivered substantial ligand-focused improvements, fragmentation framework enhancements, stability fixes, and codebase modernization. This work improves data quality, validation reliability, and developer velocity, enabling safer releases and faster iteration. Highlights include real-space map-enabled ligand validation, expanded fragmentation testing across RDKit/BNL/STI/HEX, a Polder resolution_factor bugfix, ongoing refactor with new tests, and CIF-format handling for ligands.
January 2026
1 Commits • 1 Features
Jan 1, 2026January 2026 (2026-01) monthly summary for the cctbx/cctbx_project: Delivered a precise enhancement to ligand validation by integrating an optional Quantum Mechanical Refinement (QMR) step, with configurable parameters to control QMR execution. The update improves the accuracy of ligand geometry assessments within the existing validation workflow, enabling more reliable structure-based analyses while preserving performance for standard validation runs. No major bugs were reported or fixed in this period based on available data.
1 Commits • 1 Features
Jan 1, 2026January 2026 (2026-01) monthly summary for the cctbx/cctbx_project: Delivered a precise enhancement to ligand validation by integrating an optional Quantum Mechanical Refinement (QMR) step, with configurable parameters to control QMR execution. The update improves the accuracy of ligand geometry assessments within the existing validation workflow, enabling more reliable structure-based analyses while preserving performance for standard validation runs. No major bugs were reported or fixed in this period based on available data.
January 2026
December 2025
1 Commits
Dec 1, 2025December 2025 performance summary for cctbx_project: Delivered a targeted bug fix in TableOne statistics to correctly handle twinned data when combined with model header info, improving the accuracy and reliability of resolution bin statistics and downstream analyses.
December 2025
1 Commits
Dec 1, 2025December 2025 performance summary for cctbx_project: Delivered a targeted bug fix in TableOne statistics to correctly handle twinned data when combined with model header info, improving the accuracy and reliability of resolution bin statistics and downstream analyses.
November 2025
5 Commits • 2 Features
Nov 1, 2025November 2025 monthly summary for cctbx_project focusing on TAAM_minus_IAM enhancements, dispatcher improvements, and dihedral RMS validation tests. Delivered features, improvements, and validation to improve reliability, transparency, and modeling accuracy, with business value in reproducibility and user control.
5 Commits • 2 Features
Nov 1, 2025November 2025 monthly summary for cctbx_project focusing on TAAM_minus_IAM enhancements, dispatcher improvements, and dihedral RMS validation tests. Delivered features, improvements, and validation to improve reliability, transparency, and modeling accuracy, with business value in reproducibility and user control.
November 2025
October 2025
9 Commits • 4 Features
Oct 1, 2025October 2025 monthly summary for cctbx_project: Delivered key features, robustness improvements, and refactors across hydrogen reduction, dihedral validation, and ligand processing. Implementations focused on accuracy, reliability, and maintainability of structure validation workflows.
October 2025
9 Commits • 4 Features
Oct 1, 2025October 2025 monthly summary for cctbx_project: Delivered key features, robustness improvements, and refactors across hydrogen reduction, dihedral validation, and ligand processing. Implementations focused on accuracy, reliability, and maintainability of structure validation workflows.
September 2025
14 Commits • 4 Features
Sep 1, 2025September 2025 focused on strengthening ligand validation and test infrastructure within cctbx_project. Delivered core validation workflow enhancements, expanded geometry validation metrics, and significantly improved regression testing and test coverage. The work enhances reliability of ligand interpretation, enables more robust geometric quality checks (including alternate conformations), and improves reproducibility through enhanced tests and deterministic behavior.
14 Commits • 4 Features
Sep 1, 2025September 2025 focused on strengthening ligand validation and test infrastructure within cctbx_project. Delivered core validation workflow enhancements, expanded geometry validation metrics, and significantly improved regression testing and test coverage. The work enhances reliability of ligand interpretation, enables more robust geometric quality checks (including alternate conformations), and improves reproducibility through enhanced tests and deterministic behavior.
September 2025
August 2025
13 Commits • 2 Features
Aug 1, 2025Month: 2025-08 — Focused update cycle delivering key modeling features, robust validation, and bug fixes across the cctbx_project to enhance accuracy, reliability, and business value. Key features delivered: - Restraints-aware Model Processing: Added support for processing user-supplied restraints during model processing and disabled stop_for_unknowns when restraints are available to enable more flexible model building. (Commit: f38453c32e2de7a78bf284357412c454a3950892) - Ligand Validation Improvements and Testing: Comprehensive ligand validation enhancements and testing, including improved CC calculations, logging, test coverage for occupancy/ADP, handling unknown ligands, ignore_missing_restraints, and code cleanup. (Multiple commits including 55d84f54af45dd9817e344698ca7a12f255c74ff; 3873501b0f8b9381596d9e86fa47dbf3ce445c0a; 329cba515814f0d50591b3f3331629c0e598ebf4; 46978c8acc039de357018f59c2dc6dc9542679d6; 27306db7ef2d72951b3afa4156c534833be5ffcf; 5f1dc46c6422dd51a1d0d0ad4bd92709114e7dd8; 0757235a6f63d1dddcd3c368b74799e67b3c8fee; c8e960c59c68a7f999f5d798e91a1e41f70679bb; 143b6497d261ae894bb408f5e25d3c0c5a0980af; 4b6ce9327090b34c5ba62a1faeda73d1dddade94) Major bugs fixed: - DiSCaMB Gradient Computation Corrections: Corrected DiSCaMB gradient calculations by using a consistent fmodel object and ensuring the fmodel is updated with calculated structure factors before evaluating the target function and gradients, improving accuracy and reliability. (Commits: d9696e69a37f85636b55e57244eba528c521dac6; c70152f45602b585598ec57b9149b18db245e834) Overall impact and accomplishments: - Increased modeling fidelity and resilience when restraints are present, enabling more flexible and accurate model building. - Improved gradient accuracy for DiSCaMB workflows, reducing optimization noise and increasing convergence reliability. - Expanded ligand validation and test coverage, leading to more robust ligand handling and higher confidence in CC-based quality metrics. Technologies/skills demonstrated: - Python-based scientific computing and workflow automation - Gradient-based optimization and numerical validation - Test-driven development, logging, and validation coverage - Code safety, maintainability, and cleanups Business value: - Faster iteration cycles with restraints-enabled modeling, higher-quality structural models, reduced rework from gradient-related issues, and stronger confidence in ligand-related results for downstream analysis and decision-making.
August 2025
13 Commits • 2 Features
Aug 1, 2025Month: 2025-08 — Focused update cycle delivering key modeling features, robust validation, and bug fixes across the cctbx_project to enhance accuracy, reliability, and business value. Key features delivered: - Restraints-aware Model Processing: Added support for processing user-supplied restraints during model processing and disabled stop_for_unknowns when restraints are available to enable more flexible model building. (Commit: f38453c32e2de7a78bf284357412c454a3950892) - Ligand Validation Improvements and Testing: Comprehensive ligand validation enhancements and testing, including improved CC calculations, logging, test coverage for occupancy/ADP, handling unknown ligands, ignore_missing_restraints, and code cleanup. (Multiple commits including 55d84f54af45dd9817e344698ca7a12f255c74ff; 3873501b0f8b9381596d9e86fa47dbf3ce445c0a; 329cba515814f0d50591b3f3331629c0e598ebf4; 46978c8acc039de357018f59c2dc6dc9542679d6; 27306db7ef2d72951b3afa4156c534833be5ffcf; 5f1dc46c6422dd51a1d0d0ad4bd92709114e7dd8; 0757235a6f63d1dddcd3c368b74799e67b3c8fee; c8e960c59c68a7f999f5d798e91a1e41f70679bb; 143b6497d261ae894bb408f5e25d3c0c5a0980af; 4b6ce9327090b34c5ba62a1faeda73d1dddade94) Major bugs fixed: - DiSCaMB Gradient Computation Corrections: Corrected DiSCaMB gradient calculations by using a consistent fmodel object and ensuring the fmodel is updated with calculated structure factors before evaluating the target function and gradients, improving accuracy and reliability. (Commits: d9696e69a37f85636b55e57244eba528c521dac6; c70152f45602b585598ec57b9149b18db245e834) Overall impact and accomplishments: - Increased modeling fidelity and resilience when restraints are present, enabling more flexible and accurate model building. - Improved gradient accuracy for DiSCaMB workflows, reducing optimization noise and increasing convergence reliability. - Expanded ligand validation and test coverage, leading to more robust ligand handling and higher confidence in CC-based quality metrics. Technologies/skills demonstrated: - Python-based scientific computing and workflow automation - Gradient-based optimization and numerical validation - Test-driven development, logging, and validation coverage - Code safety, maintainability, and cleanups Business value: - Faster iteration cycles with restraints-enabled modeling, higher-quality structural models, reduced rework from gradient-related issues, and stronger confidence in ligand-related results for downstream analysis and decision-making.
July 2025
24 Commits • 17 Features
Jul 1, 2025July 2025 performance summary for cctbx_project. Delivered enhancements to metrics, reporting, and data analysis pipelines that improve structural interpretation, reproducibility, and automation readiness. Notable feature deliveries include metric updates, enhanced summaries, and richer result printing; accompanied by stabilizing fixes and workflow-friendly data management improvements. ADP and occupancy analytics were refined for more accurate residue-level statistics, and data management options were expanded with configurable logging. Overall, these changes increase analytic accuracy, enable simpler downstream reporting, and reduce manual intervention.
24 Commits • 17 Features
Jul 1, 2025July 2025 performance summary for cctbx_project. Delivered enhancements to metrics, reporting, and data analysis pipelines that improve structural interpretation, reproducibility, and automation readiness. Notable feature deliveries include metric updates, enhanced summaries, and richer result printing; accompanied by stabilizing fixes and workflow-friendly data management improvements. ADP and occupancy analytics were refined for more accurate residue-level statistics, and data management options were expanded with configurable logging. Overall, these changes increase analytic accuracy, enable simpler downstream reporting, and reduce manual intervention.
July 2025
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025: Delivered a new command-line tool phenix.TAAM_minus_IAM to compute TAAM-IAM difference maps. Integrated PyDiscamb with the cctbx framework to generate MTZ outputs, added flexible input options (resolution limit or reflection file), and implemented validation for crystal symmetry and input data to ensure robust TAAM/IAM analyses. This work enables reproducible, scriptable TAAM/IAM workflows and accelerates data quality assessment.
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025: Delivered a new command-line tool phenix.TAAM_minus_IAM to compute TAAM-IAM difference maps. Integrated PyDiscamb with the cctbx framework to generate MTZ outputs, added flexible input options (resolution limit or reflection file), and implemented validation for crystal symmetry and input data to ensure robust TAAM/IAM analyses. This work enables reproducible, scriptable TAAM/IAM workflows and accelerates data quality assessment.
May 2025
2 Commits • 2 Features
May 1, 2025May 2025 monthly summary for cctbx/cctbx_project: Focused on strengthening validation workflows and test coverage that underpin reliable structure-factor analysis and ligand modeling. Key features delivered include Discamb module Fcalc validation tests against OLEX data and a ligand validation workflow refactor leveraging reduce2 for hydrogen placement and data_manager integration. These workstreams enhance correctness, robustness, and data handling across structure-factor calculations and ligand validation, reducing downstream risk and enabling faster, more trustworthy analysis. No major bugs reported; tests updated to maintain robustness. Technologies demonstrated include Python test frameworks, test-driven development, integration with data_manager, and functional refactor of validation pipelines. Business value: improved reliability of Fcalc comparisons with external data, accelerated validation cycles for ligands, and stronger alignment with data management practices.
2 Commits • 2 Features
May 1, 2025May 2025 monthly summary for cctbx/cctbx_project: Focused on strengthening validation workflows and test coverage that underpin reliable structure-factor analysis and ligand modeling. Key features delivered include Discamb module Fcalc validation tests against OLEX data and a ligand validation workflow refactor leveraging reduce2 for hydrogen placement and data_manager integration. These workstreams enhance correctness, robustness, and data handling across structure-factor calculations and ligand validation, reducing downstream risk and enabling faster, more trustworthy analysis. No major bugs reported; tests updated to maintain robustness. Technologies demonstrated include Python test frameworks, test-driven development, integration with data_manager, and functional refactor of validation pipelines. Business value: improved reliability of Fcalc comparisons with external data, accelerated validation cycles for ligands, and stronger alignment with data management practices.
May 2025
March 2025
18 Commits • 6 Features
Mar 1, 2025March 2025 monthly summary for cctbx_project focusing on key features delivered, major fixes, and overall impact. This month, the team delivered substantial feature enhancements and strengthened test coverage across the repo, while also performing targeted cleanup to improve maintainability and tooling discoverability.
March 2025
18 Commits • 6 Features
Mar 1, 2025March 2025 monthly summary for cctbx_project focusing on key features delivered, major fixes, and overall impact. This month, the team delivered substantial feature enhancements and strengthened test coverage across the repo, while also performing targeted cleanup to improve maintainability and tooling discoverability.
February 2025
2 Commits
Feb 1, 2025February 2025 monthly summary for the cctbx project focused on robustness improvements in Reduce2 for edge-case models and strengthened test coverage. The work delivered resolves a single-atom model handling edge case and ensures model initialization precedes hydrogen-atom checks, reducing runtime errors when processing small models.
2 Commits
Feb 1, 2025February 2025 monthly summary for the cctbx project focused on robustness improvements in Reduce2 for edge-case models and strengthened test coverage. The work delivered resolves a single-atom model handling edge case and ensures model initialization precedes hydrogen-atom checks, reducing runtime errors when processing small models.
February 2025
January 2025
9 Commits • 1 Features
Jan 1, 2025January 2025 performance summary for cctbx/cctbx_project. Delivered Scattering Table Management and Consistency enhancements to propagate scattering_table into the xray_structure registry, with a safe getter and ensured propagation when setting within model. Implemented preservation of registry parameters across selections and robust behavior when the registry is uninitialized. Expanded and hardened tests verifying consistency across model objects, X-ray structures, and data managers, and updated test infrastructure. Included targeted test updates to Discamb enabling I and Rh for wk1995, strengthening chemistry-specific coverage. Result: improved correctness, reliability, and developer confidence in scattering table handling, enabling safer analytics workflows for crystallography."
January 2025
9 Commits • 1 Features
Jan 1, 2025January 2025 performance summary for cctbx/cctbx_project. Delivered Scattering Table Management and Consistency enhancements to propagate scattering_table into the xray_structure registry, with a safe getter and ensured propagation when setting within model. Implemented preservation of registry parameters across selections and robust behavior when the registry is uninitialized. Expanded and hardened tests verifying consistency across model objects, X-ray structures, and data managers, and updated test infrastructure. Included targeted test updates to Discamb enabling I and Rh for wk1995, strengthening chemistry-specific coverage. Result: improved correctness, reliability, and developer confidence in scattering table handling, enabling safer analytics workflows for crystallography."
November 2024
18 Commits • 4 Features
Nov 1, 2024November 2024 monthly summary for cctbx_project focused on strengthening validation, tooling, and robustness across core structure-determination workflows. Delivered end-to-end validation and tooling enhancements, with notable improvements in test coverage, reliability, and data integrity for downstream science activities.
18 Commits • 4 Features
Nov 1, 2024November 2024 monthly summary for cctbx_project focused on strengthening validation, tooling, and robustness across core structure-determination workflows. Delivered end-to-end validation and tooling enhancements, with notable improvements in test coverage, reliability, and data integrity for downstream science activities.
November 2024
October 2024
5 Commits • 2 Features
Oct 1, 2024October 2024 monthly summary for the cctbx_project: Implemented DiSCaMB Test Suite Expansion and plotting enhancements, delivering broader coverage across structure factor validations and enabling visual diagnostics. This work strengthens cross-tool reliability (cctbx, pyDiSCaMB, DiSCaMB) and supports regression protection moving into Q4.
October 2024
5 Commits • 2 Features
Oct 1, 2024October 2024 monthly summary for the cctbx_project: Implemented DiSCaMB Test Suite Expansion and plotting enhancements, delivering broader coverage across structure factor validations and enabling visual diagnostics. This work strengthens cross-tool reliability (cctbx, pyDiSCaMB, DiSCaMB) and supports regression protection moving into Q4.
Activity
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Quality Metrics
Correctness88.6%
Maintainability85.0%
Architecture82.6%
Performance78.0%
AI Usage20.4%
Skills & Technologies
Programming Languages
C++PDBPython
Technical Skills
BioinformaticsBug FixBug FixingC++ (via C extensions)C++ (via CCTBX)C++ (via Python bindings)CCTBXCI/CDChemistryClean CodeCode AnnotationCode ArchivingCode CleanupCode RefactoringCommand Line Interface Development
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