title: Convergence of the multipole expansion for 1,2 Coulomb interactions: The modified multipole shifting algorithm.
abstract: A force field that accounts for the quantum chemical reality of interacting atoms must include Coulomb interactions between bonded atoms. The short-range nature of such 1,2 interactions necessitates atomic multipole moments in addition to point charges. However, the close proximity of bonded atoms would normally lead to a divergent multipolar expansion. A special algorithm presented here, within the scope of the previously presented multipole shifting method [M. Rafat and P. L. A. Popelier, J. Chem. Phys. 124, 144102 (2006)], shows that convergence can nevertheless be achieved by a suitable selection of multipole displacements. The algorithm is applied to improve the convergence of the multipolar expansion within the quantum theory of atoms in molecules approach.
authors.affiliation: Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006-Oviedo, Spain.
authors.forename: C J F
authors.initials: CJ
authors.lastname: Solano
authors.forename: A Martín
authors.initials: AM
authors.lastname: Pendás
authors.forename: E
authors.initials: E
authors.lastname: Francisco
authors.forename: M A
authors.initials: MA
authors.lastname: Blanco
authors.forename: P L A
authors.initials: PL
authors.lastname: Popelier
mesh_terms: D000465:Algorithms; D011789:Quantum Theory; D055672:Static Electricity