title: Steric effect: a quantitative description from density functional theory.
abstract: The concepts of steric energy, steric potential, and steric charge are introduced within the density functional theory framework. The steric energy, representing a hypothetical state with all electrons packed into the lowest orbital and other effects entirely excluded, is a measure of the intrinsic space occupied by an electronic system. It is exclusive, repulsive, and extensive, and it vanishes for homogeneous electron gas. When Bader's zero-flux boundary condition is adopted, atoms in molecules are found to achieve balanced steric repulsion among one another with vanished steric energy density interfaces. A few molecular systems involving conformation changes and chemical reactions have been investigated to examine the relative contribution of the steric and other effects, providing insights for a few controversial topics from a different perspective.
authors.affiliation: The Renaissance Computing Institute (RENCI), University of North Carolina, Chapel Hill, North Corolina 27599-3420, USA. shubin@email.unc.edu
authors.forename: Shubin
authors.initials: S
authors.lastname: Liu