CSMSL.Chemistry.Element.AddIsotope C# (CSharp) Method

        internal Isotope AddIsotope(int atomicNumber, double atomicMass, float abundance)
        {
            var isotope = new Isotope(this, atomicNumber, atomicMass, abundance);
            if (Isotopes.ContainsKey(atomicNumber))
                return isotope;
            Isotopes.Add(atomicNumber, isotope);
            TotalAbundance += abundance;
            _totalMass += abundance*atomicMass;
            AverageMass = _totalMass/TotalAbundance;
            if (PrincipalIsotope != null && !(abundance > PrincipalIsotope.RelativeAbundance))
                return isotope;
            if (PrincipalIsotope != null)
            {
                PrincipalIsotope.IsPrincipalIsotope = false;
            }
            PrincipalIsotope = isotope;
            PrincipalIsotope.IsPrincipalIsotope = true;
            return isotope;
        }

        /// <summary>
        /// Load a xml file containing elemental and isotopic data into the periodic table
        /// </summary>
        public void LoadElements(Stream elementsListXml)
        {
            using (XmlReader reader = XmlReader.Create(elementsListXml))
            {
                reader.ReadToFollowing("PeriodicTable");
                _uniqueId = int.Parse(reader.GetAttribute("defaultID"));
                int isotopes = int.Parse(reader.GetAttribute("isotopesCount"));
                _isotopes = new Isotope[isotopes];
                while (reader.ReadToFollowing("Element"))
                {
                    reader.ReadToFollowing("Name");
                    string name = reader.ReadElementContentAsString();
                    reader.ReadToFollowing("Symbol");
                    string symbol = reader.ReadElementContentAsString();
                    reader.ReadToFollowing("AtomicNumber");
                    int atomicnumber = reader.ReadElementContentAsInt();
                    reader.ReadToFollowing("ValenceElectrons");
                    int valenceElectrons = reader.ReadElementContentAsInt();
                    Element element = new Element(name, symbol, atomicnumber, valenceElectrons);

                    bool isStartNode = reader.ReadToNextSibling("Isotope");
                    while(isStartNode)
                    {
                        string unqiueId = reader.GetAttribute("uniqueID");
                        reader.ReadToFollowing("Mass");
                        double mass = reader.ReadElementContentAsDouble();
                        reader.ReadToFollowing("MassNumber");
                        int massNumber = reader.ReadElementContentAsInt();
                        reader.ReadToFollowing("RelativeAbundance");
                        float abundance = reader.ReadElementContentAsFloat();
                        if (abundance > 0)
                        {
                            Isotope isotope = element.AddIsotope(massNumber, mass, abundance);

                            if (unqiueId != null)
                            {
                                int uniqueId = int.Parse(unqiueId);
                                isotope.UniqueId = uniqueId;
                                _isotopes[uniqueId] = isotope;
                            }
                            else
                            {
                                isotope.UniqueId = _uniqueId;
                                _isotopes[_uniqueId++] = isotope;
                            }
                        }
                        if (!reader.IsStartElement("Isotope"))
                            isStartNode = reader.ReadToNextSibling("Isotope");
                    }
                    AddElement(element);
                }
            }

            if(_isotopes.Length != _uniqueId)
                Array.Resize(ref _isotopes, _uniqueId);
        }