package jsci.chemistry;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import jsci.physics.*;

/**
* A class representing molecules.
* @version 0.2
* @author Mark Hale
*/
public class Molecule extends Particle {
        /**
        * Atoms.
        */
        private final Set atoms = new HashSet();
        /**
        * Constructs a molecule from a chemical formula.
        */
        public Molecule(String formula) {
                if(formula == null || formula.length() == 0)
                        throw new IllegalArgumentException("Formula cannot be null or empty.");
                int startPos = 0, endPos;
                boolean isNumber = false;
                String symbol = null;
                int count;
                for(int i=1; i