The main function introduction and example code of Open Babel class library

Open Babel is an open source chemical information tool package for the fields of chemical molecules, theoretical computing, and drug discovery.It provides a powerful and flexible API that can be used for different programming languages, such as C ++, Python and Java.The main functions and example code of the Open Babel class library are introduced below. 1. Chemical conversion: Open Babel can convert the molecular structure from one file format to another format, supporting a variety of commonly used chemical file formats including SMILES, Inchi, PDB, MOL.The example code is as follows: python import openbabel as ob # Object of OPEN BABEL mol = ob.OBMol() # Read the molecular file obconversion = ob.OBConversion() obconversion.SetInAndOutFormats('pdb', 'mol2') obconversion.ReadFile(mol, 'input.pdb') # Convert the molecular object to mol2 format obconversion.WriteFile(mol, 'output.mol2') 2. Chemical descriptor calculation: Open Babel supports various chemical descriptors of computing molecules, such as molecular weight, relative molecular mass, chemical bond length, atomic charge, etc.The example code is as follows: python import openbabel as ob # Object of OPEN BABEL mol = ob.OBMol() # Read the molecular file obconversion = ob.OBConversion() obconversion.ReadFile(mol, 'input.pdb') # Calculating molecular descriptor fm = ob.OBForceField() fm.Setup(mol) fm.DiverseTemplates("uff") fm.Description("Energy") energy = fm.Energy() # Print molecular descriptor results print("Energy:", energy) 3. Reaction forecast: Open Babel also supports the prediction and generation of reaction.It can predict the generated products according to the given reaction and reaction conditions.The example code is as follows: python import openbabel as ob # reaction = ob.OBReaction() # reactant1_mol = ob.OBMol() obconversion = ob.OBConversion() obconversion.ReadString(reactant1_mol, 'CCO') reaction.AddReactant(reactant1_mol) reactant2_mol = ob.OBMol() obconversion.ReadString(reactant2_mol, 'ClC1=CC=CC=C1') reaction.AddReactant(reactant2_mol) # Add reaction condition reaction.SetData("Comment", "Conditions: heat, reflux") # product = ob.OBMol() reaction.PredictProducts(product) # Output product molecular structure obconversion.WriteFile(product, 'output.mol2') The above is the main function and example code of the Open Babel Library.Before using Open Babel, you need to ensure that the corresponding Open Babel library has been installed and configured according to your programming language.The detailed configuration method can be found in the official documentation of Open Babel.