On the occasion of the 50th anniversary of the journal Theoretical Chemistry Accounts, leading researchers in theoretical chemistry present current and forward-looking perspectives on major developments in the field. Originally published in the journal, these outstanding contributions are now available in a hardcover print format. This collection will be of benefit in particular to those research groups and libraries that have chosen to have only electronic access to the journal.With contributions from Christopher J. Cramer, Gino A. DiLabio, Filipp Furche, Sophya Garashchuk, Peter M.W. Gill, Hua Guo, So Hirata, Brian K. Kendrick, Hans Lischka, Wenjian Liu, Fernando R. Ornellas, Irina Paci, Kirk A. Peterson, Markus Reiher, Jeffrey R. Reimers, Manuel Smeu, Seiichiro Ten-no, Diego Troya, Donald G. Truhlar, Christoph van Wüllen, Dong H. Zhang