XDrawChem
XDrawChem is a free software program for drawing chemical structural formulas, available for Windows, Unix, and Mac OS. It is distributed under the GNU GPL.
Major features
- Fixed length and fixed angle drawing
- Automatic alignment of figures
- Detection of structures, text, and arrows, and their automatic placement
- Can automatically draw rings and other structures - has all standard amino acids and nucleic acids in a built-in library
- Retrieval of structures from a network database based on CAS number, formula, or name
- Retrieval of information on a molecule based on a drawing
- Symbols such as partial charge and radicals
- Reading MDL Molfiles, CML (Chemical Markup Language), ChemDraw binary format, ChemDraw XML text format
- Writing MDL Molfiles, CML, ChemDraw XML text format
- Integration with OpenBabel, allowing XDrawChem to read and write over 20 different chemical file formats.
- Image export in Portable Network Graphics (PNG), Windows bitmap, Encapsulated PostScript (EPS), and Scalable Vector Graphics (SVG)
- 3D structure generation with the help of the external program BUILD3D
- Simple spectra predictions, including 13C-NMR, 1H-NMR (based on additive rules and functional group lookup methods), and IR
- Simple property estimation, including pKa, octanol-water partition coefficient, and gas-phase enthalpy change.