CSMSL.Chemistry.PeriodicTable.TryGetElement C# (CSharp) Method

        public static bool TryGetElement(string elementSymbol, out Element element)
        {
            return _elements.TryGetValue(elementSymbol, out element);
        }

        /// <summary>
        /// Parses a string representation of chemical formula and adds the elements
        /// to this chemical formula
        /// </summary>
        /// <param name="formula">the Chemical Formula to parse</param>
        private void ParseString(string formula)
        {
            if (string.IsNullOrEmpty(formula))
            {
                return;
            }

            if (!IsValidChemicalFormula(formula))
            {
                throw new FormatException("Input string for chemical formula was in an incorrect format");
            }

            foreach (Match match in FormulaRegex.Matches(formula))
            {
                string chemsym = match.Groups[1].Value; // Group 1: Chemical Symbol

                Element element;
                if (PeriodicTable.TryGetElement(chemsym, out element))
                {
                    Isotope isotope = element.PrincipalIsotope; // Start with the most abundant (principal) isotope

                    if (chemsym.Equals("D"))                    // Special case for Deuterium
                    {
                        isotope = element.Isotopes[2];
                    }
                    else if (match.Groups[2].Success) // Group 2 (optional): Isotope Mass Number
                    {
                        isotope = element[int.Parse(match.Groups[2].Value)];
                    }

                    int sign = match.Groups[3].Success ? // Group 3 (optional): Negative Sign
                               -1 :
                               1;

                    int numofelem = match.Groups[4].Success ? // Group 4 (optional): Number of Elements
                                    int.Parse(match.Groups[4].Value) :
                                    1;

                    Add(isotope, sign * numofelem);
                }
                else
                {
                    throw new ArgumentException(string.Format("The chemical Symbol '{0}' does not exist in the Periodic Table", chemsym));
                }
            }
        }