Quantum Chemistry and Chemical Physics

By the 1950s, there was a recognized academic field of theoretical chemistry that encompassed the subfields or disciplines of physical chemistry, physical organic chemistry, quantum chemistry, and chemical physics. In this chapter, we will consider the physicists who developed quantum mechanics and applied it to molecules in the 1920s, the physicists and chemists who created quantum chemistry and chemical physics in the late 1920s and 1930s, and the coming of age of quantum chemistry by around 1950. 

Quantum Chemistry and Chemical Physics in the 1930s and 1940s... 

What was the distinction between quantum chemistry and chemical physics After the Journal of Chemical Physics was established, it was easy to say that chemical physics was anything found in the new journal. This included molecular spectroscopy and molecular structures, the quantum mechanical treatment of electronic structure of molecules and crystals and the problem of chemical binding, the kinetics of chemical reactions from the standpoint of basic physical principles, the thermodynamic properties of substances and calculation by statistical mechanical methods, the structure of crystals, and surface phenomena. 

The disciplinary titles of the practitioners of quantum chemistry and chemical physics varied. Pauling initially wanted his title at Caltech to be professor of theoretical chemistry and mathematical physics, but he accepted CalTech s dropping "mathematical physics" 115 and later preferred to be known as a chemist. 116 Slater always had his principal appointment in a physics department. Mulliken, who had taken his degree at Chicago in chemistry, returned in 1928 as associate professor of physics and retired in 1983 as professor of chemistry and physics. 117... 

Van Vleck, working at the borderline of quantum chemistry and chemical physics, saw things similarly. 

Chapter 9 of Nye s book is devoted to Quantum chemistry and chemical physics, 1920-1950 , with sections on the application of quantum mechanics to molecules in the 1920s, chemists and quantum mechanics in the 1920s and 1930s, and quantum chemistry and chemical physics in the 1930s and 1940s. 

Coupled Differential Equations. - There are many problems in theoretical physics and theoretical chemistry, atomic physics, physical chemistry, quantum chemistry and chemical physics which can be transformed to the solution of coupled differential equations of the Schrodinger type. 

This venerable book was written in 1935, shortly after the birth of modern quantum mechanics. Nevertheless, it remains one of the best sources for students seeking to gain an understanding of quantum-mechanical principles that are relevant in chemistry and chemical physics. Equally outstanding jobs are done in dealing with both quantitative and qualitative aspects of the subject. More accessible to most chemists than Landau and Lifschitz. 

PRINCIPLES OF QUANTUM MECHANICS as Applied to Chemistry and Chemical Physics... 

This text presents a rigorous mathematieal aeeount of the principles of quantum meehanies, in partieular as applied to chemistry and chemical physics. Applications are used as illustrations of the basic theory. 

But, we expect that the majority of readers will be those with only a rudimentary command of quantum chemistry and chemical bonding theory (e.g., at the level of junior-year physical chemistry course) who wish to learn more about the emerging ab initio and density-functional view of molecular and supramolecular interactions. While this is not a textbook in quantum chemistry per se, we believe that the book can serve as a supplement both in upper-level undergraduate courses and in graduate courses on modern computational chemistry and bonding theory. 

D. D. Fitts, Principles of Quantum Mechanics as Allied to Chemistry and Chemical Physics, Cambridge University Press, Cambridge, 1999. 

The application of wavelet analysis to physical chemistry and chemical physics is in its infancy. The present survey indicates that there are many opportunities remaining to advance the fields of quantum chemistry, chemical dynamics and chemical kinetics by using this powerful new tool. 

Physical chemistry as a separate pursuit has its roots in the nineteenth century, but it grew, matured, and blossomed in the twentieth. The two areas in particular that belong to the 1900s—quantum chemistry and chemical kinetics— have had tantalizing success with simple systems, but they are far from complete theories. Likewise kinetics and thermodynamics, which have enormous predictive and explanatory powers for equilibrium systems, have yet to be completely developed for nonideal and nonequilibrium systems. But the work that has been done shows promise of remarkable revelations just ahead. 

McWeeny, 1973] R. McWeeny. Quantum. Mechanics Methods and Basic Applications. The International Encyclopedia of Physical Chemistry and Chemical Physics Volume 2 2 (Oxford Pergamon Press), 1973. 

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