CASTRA: crystallographic analysis and structural transformation tool
摘要
CASTRA is an advanced graphical user interface (GUI) package for manipulating, visualizing, and analyzing Crystallographic Information Files (CIFs). It facilitates a wide range of crystallographic tasks and improves the effectiveness and accuracy of research through its enhanced functions. CASTRA automates the extraction and transformation of atomic coordinates from molecular coordinate files generated by the PIXEL software suite to generate dimeric assemblies. Significant translations are identified and applied to produce translated CIFs, facilitating accurate reconstruction of molecular dimers. Another Python module was developed to automate the calculation of enrichment ratios using contact data from CrystalExplorer, facilitating the quantitative assessment of atomic interaction preferences by comparing observed surface contacts against random distribution models. This module generates comprehensive contact matrices and graphical visualizations, offering crystallographers an intuitive platform for the detailed analysis and interpretation of molecular packing and interaction patterns within crystal structures. A Python-based module in CASTRA classifies weak interactions (hydrogen bonds vs. van der Waals) using atomic coordinates and electron density data from quantum theory of atoms in molecules (QTAIM). It applies geometric and empirical rules to analyze bond critical point (BCP) distances and van der Waals radii for automated, accurate classification. The CASTRA software computes bond lengths, bond angles, and torsion angles, including comparisons between X-ray crystallographic and Gaussian-optimized structures for detailed structural analysis. The CASTRA tool is available as an open-source package at https://github.com/UdaykumarMani24/CASTRA.git.