22 research outputs found
Distributed Multipoles from a Robust Basis-Space Implementation of the Iterated Stockholder Atoms Procedure
The
recently developed iterated stockholder atoms (ISA) approach
of Lillestolen and Wheatley (<i>Chem. Commun.</i> <b>2008</b>, 5909) offers a powerful method for defining atoms in
a molecule. However, the real-space algorithm is known to converge
very slowly, if at all. Here, we present a robust, basis-space algorithm
of the ISA method and demonstrate its applicability on a variety of
systems. We show that this algorithm exhibits rapid convergence (taking
around 10–80 iterations) with the number of iterations needed
being unrelated to the system size or basis set used. Further, we
show that the multipole moments calculated using this basis-space
ISA method are as good as, or better than, those obtained from Stone’s
distributed multipole analysis (<i>J. Chem. Theory Comput.</i> <b>2005</b>, <i>1</i>, 1128), exhibiting better
convergence properties and resulting in better behaved penetration
energies. This can have significant consequences in the development
of intermolecular interaction models