This book covers a range of new research on computational quantum chemistry, along with a special section devoted to exotic carbon allotropes and spiro quantum theory. The section on spiro quantum theory covers the technical presentation of the ideas surrounding the emergence of a synthetic, analytical, and theoretical spiro quantum chemistry edifice, as well as a chemical topology scheme that successfully describes molecules and patterns, including the hydrocarbons and allotropes of carbon. The second part of the book covers a range of new research on computational quantum chemistry.