Atomic level simulations on a million particles: The cell multipole method for Coulomb and London nonbond interactions

Ding, Hong-Qiang; Karasawa, Naoki; Goddard, William A.
September 1992
Journal of Chemical Physics;9/15/1992, Vol. 97 Issue 6, p4309
Academic Journal
The N2 computations implicit in the Coulomb and other long range interactions remain the critical bottleneck in atomic-level simulations of the structure and dynamics of large systems. We report here the cell multipole method which scales linearly with N and requires only modest memory. To demonstrate the feasibility of this approach, we report systematic calculations on realistic polymer systems with up to 1.2 million atoms on a laboratory workstation. The method becomes faster than the exact method for systems of 300 atoms, and for a 1.2 million-atom polymer, it is 2377 times faster. The method treats a class of interactions of the form qiqj/rijp, which includes Coulomb (p=1), London dispersion (p=6), or shielded Coulomb (p=2) interactions. This method is well suited for highly parallel and vector computers.


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