Solvent-scaling as an alternative to coarse-graining in adaptive-resolution simulations: The adaptive solvent-scaling (AdSoS) scheme

A new approach termed Adaptive Solvent-Scaling (AdSoS) is introduced for performing simulations of a solute embedded in fine-grained (FG) solvent region itself surrounded by coarse-grained (CG) region, with continuous FG ? CG switching the resolution across buffer layer. Instead relying on distinct model, AdSoS scheme based models defined dimensional scaling factor s, accompanied an s-dependent modulation atomic masses and interaction parameters. The latter changes are designed to achieve isomorphism between dynamics models, preserve dispersive dielectric solvation properties respect at resolution. This offers number advantages compared traditional coarse-graining: (i) parameters immediately related those model (no need parameterize model); (ii) nearly ideal mixing expected variants similar s-values (ideal holding limit identical s-values); (iii) relaxation timescales should be preserved dynamical acceleration typical coarse-graining); (iv) graining level NG (number molecules represented one molecule) can chosen arbitrarily (in particular, = s3 not necessarily integer); (v) adaptive-resolution scheme, this varied continuously as function position (without requiring bundling mechanism), variation occurs constant particles per molecule occurrence fractional degrees freedom layer). By construction, minimizes thermodynamic mismatch different regions system, leading homogeneous scaled density s3?. Residual artifacts surface boundary layer easily corrected means grid-based biasing potential constructed preliminary pure-solvent simulation. article introduces provides initial application pure liquids solute) Lennard-Jones plus Coulomb interactions slab geometry.