The direct inversion of the iterative subspace (DIIS) solution to the iterative integral equation formalism polarized continuum
model (IEF–PCM, 2001
Theor. Chem. Acc. 105:1186) is applied to the effective fragment potential IEF–PCM interface (2002 J Chem Phys 116:5023). Compared to a direct
matrix-inversion solution, the DIIS–PCM is up to an order of magnitude more efficient both in computing time and memory requirements
for large systems. Multipole treatments of long-range electrostatic interactions further reduce the computing time by up to
50%. All the CPU intensive computations are parallelized. The data presented in this paper demonstrate that use of the iterative
IEF–PCM is an efficient way to model bulk solvation of large biomolecules described by QM/MM.
Keywords: Continuum solvation – Quantum mechanics/molecular mechanics – Polarized continuum model – Protein
Received: 18 October 2002 / Accepted: 13 November 2002 / Published online: 21 March 2003
Acknowledgements. This work was supported by a Research Innovation Award from the Research Corporation, and a type G starter grant from the
Petroleum Research Fund. H.L. gratefully acknowledges a predoctoral fellowship from the Center for Biocatalysis and Bioprocessing
at the University of Iowa. The calculations wer performed on IBM RS/6000 workstations obtained through a CRIF grant from the
NSF (CHE-9974502). We thank Michael Schmidt for a careful reading of the manuscript, and Laurent Jay for useful discussions.
Correspondence to: J. H. Jensen e-mail: jan-jensen@uiowa.edu