Mary Eugenia Kapp was born on April 15, 1909, in Mount Airy, North Carolina. She received an A.B. degree from the University of North Carolina at Greensboro, an M.A. from Duke University, and the Ph.D. in analytical chemistry from the University of North Carolina at Chapel Hill.

From 1931 to 1934 she was head of the science department at Blackstone College, and from 1938 to 1939 she was head of the science department at Averett College. Dr. Kapp was a chemistry instructor at Sophie Newcomb College of Tulane University in New Orleans from 1939 to 1940. In 1940, she joined the faculty of Richmond Professional Institute of the College of William and Mary as an assistant professor of chemistry and head of the chemistry department. During World War II, Dr. Kapp worked as assistant chief of chemistry for DuPont in Richmond. Returning to RPI in 1946, she was promoted to associate professor.

In 1952, she was promoted to professor and made chairperson of the School of Applied Sciences, and she continued as chair of the chemistry department in that school. This school was reorganized in 1966 and made a part of the newly created School of Arts and Sciences, where Dr. Kapp remained as chairperson.  She continued in this position when RPI and the Medical College of Virginia merged to become Virginia Commonwealth University in 1968 and until her retirement in 1972. Dr. Kapp was a fellow of the Virginia Academy of Sciences and a member of the American Chemical Society. In 1952 she became the first woman elected chair of the society’s Virginia Section, and she received that group’s Distinguished Service Award in 1969. She was a member of the American Institute of Chemists and the Southern Association of Science and Industry, and she was listed in Who’s Who in America.

Even affordable electronic structure calculations based on modern density functionals are capable of predicting energy differences such as bond strengths or the magnitude of non-covalent interactions to within a few percent of reference values. This is a remarkable achievement of computational quantum chemistry, but the results are simply numerical experiments that do not by themselves convey any deeper chemical understanding. For this purpose, other tools are needed.

This talk will center on describing and applying one useful class of computational methods that aim to address the challenge of interpreting such energy differences: energy decomposition analysis (EDA) [1]. An EDA disentangles energy differences into a sum of several contributions that have distinct physical origins, such as permanent and induced electrostatics, Pauli repulsion, dispersion, charge-transfer and, in the case of chemical bonds, electron pair formation. EDA is increasingly used for applications such as understanding non-covalent interactions, chemical bonds, and even aspects of chemical catalysis and reactivity. A range of hopefully interesting chemical examples will be presented to illustrate both present progress and remaining controversies.

[1] Y. Mao, M. Loipersberger, P. R. Horn, A. Das, O. Demerdash, D. S. Levine, S. P. Veccham, T. Head-Gordon, and M. Head-Gordon, “From intermolecular interaction energies and observable shifts to component contributions and back again: A tale of variational energy decomposition analysis”, Annu. Rev. Phys. Chem. 72, 641–666 (2021).