Source code:
@Grab(group='org.openscience.cdk', module='cdk-bundle', version='2.9')
import org.openscience.cdk.interfaces.*
import org.openscience.cdk.*;
hydrogen = new Atom("H")
radicalElectron =
new SingleElectron(hydrogen)
hydrogenRadical = new AtomContainer()
hydrogenRadical.addAtom(hydrogen)
hydrogenRadical.addSingleElectron(radicalElectron)
Output: