Simmonett, AndrewGilbert, AndrewGill, Peter2015-12-130026-8976http://hdl.handle.net/1885/82039Motivated by the Legendre expansion of the electrostatic potential (ESP), we propose a method for obtaining atomic point-charges for a molecule based on reproducing the low-order multipole moments of the system. The resulting multipole-derived charges (MDCs) are well defined, do not require sampling of the ESP at grid points around the molecule and provide excellent reproduction of the electrostatic potential. No constraints are placed on the magnitude of the atomic charges.Keywords: Constraint theory; Electric fields; Mathematical models; Atomic charges; Electrostatic potential (ESP); Multipole-derived charges (MDC); Molecular physics200510.1080/002689705001879102015-12-11