Chapter 7 - Atom-Centered Potentials for Noncovalent Interactions and Other Applications

Abstract

This chapter provides an overview of the use of atom-centered potentials (ACPs) in a variety of applications. First, we briefly review the development of ACPs and the underlying theory for application as effective core potentials. ACPs have been used extensively by the modeling community since the early days of computational chemistry and condensed matter physics to calculate the properties of systems containing atoms in the lower part of the periodic table and for solid phase systems. We then outline more recent work that applied the concept of ACPs to tackle the “link atom” problem that is present in the application of quantum mechanical–molecular mechanics modeling of large systems in which the quantum mechanical region of interest is covalently bonded to the molecular mechanics regime. The development of this new kind of ACP, in which all but one electron of carbon (or silicon) are represented by potentials, provides an interesting approach to artificially limiting the quantum mechanical region. A review of later work that leveraged the flexibility associated with ACPs to correct for the absence of dispersion physics in conventional density-functional theory methods is then described. In this context, the ACPs are termed dispersion-correcting potentials (or DCPs). By the nature of their development, which is entirely empirical, DCPs correct for additional short-comings present in conventional density-functional theory modeling techniques, including those of the underlying functional and those associated with the use of small atom-centered basis sets. This chapter closes with some prospects for future applications of ACPs.