York, DM; Lee, T-S; Yang, W, *Parameterization and efficient implementation of a solvent model for linear-scaling semiempirical quantum mechanical calculations of biological macromolecules*,
Chemical Physics Letters, vol. 263 no. 1-2
(1996),
pp. 297-304 .
**Abstract:**

*A method is developed to include solvation effects in linear-scaling semiempirical quantum calculations. Favorable scaling of computational effort for large molecules is achieved using a preconditioned conjugate gradient technique in conjunction with a linear-scaling recursive bisection method for evaluation of electrostatic interactions. The method requires approximately 30% computational overhead relative to gas-phase calculations. Effective atomic radii for biological macromolecules are derived from fitting to experimental and theoretical solvation energies for small molecules homologous to amino-and nucleic acid residues.*