Source code:
@Grab(group='org.openscience.cdk', module='cdk-bundle', version='2.9')
import org.openscience.cdk.interfaces.*;
import org.openscience.cdk.*;
import org.openscience.cdk.config.Elements;
IAtom atom = new Atom(Elements.CARBON);
assert atom.atomicNumber == 6;
println "atomic number: " +
atom.atomicNumber
Output:
atomic number: 6