solvation -continuum solvation model control variable
DESCRIPTION
The solvation variable determines the use of a continuum solvation model to represent solvation into water. If solvation is set to ON, the Hartree potential is replaced by the solution of a Poisson problem with a dielectric function representing the screening of the electrostatic potential by the dipolar solvent.
The dielectric function used in the Poisson problem is based on the electronic density and is well defined only for reasonable electronic densities. Before turnig solvation ON, one should make sure that one has reached a resonable electronic density in order to avoid convergence problems in the Poisson solver. The Poisson solver uses the same grid as the real-space grid used by FFT. The multigrid solver requires a grid size divisible by 4 in each direction. At this time, it is not always the case for the FFT grid. The user should select an energy cutoff that provides such a grid. Since Dirichlet boundary conditions are used for this model, the translational invariance is lost and one should make sure that the molecule computed is centered around (0,0,0).
The use of the solvation model is incompatible with the truncated potentials (i.e. requires tcp OFF) and/or the stress (i.e. requires stress OFF). Also the model should be used only with the PBE exchange-correlation functional to produce correct physical results.
DEFAULT VALUE
OFF
ALLOWED VALUES
ON, OFF
REFERENCE
J.-L. Fattebert and F. Gygi, "Density Functional theory for efficient ab initio molecular dynamics simulations in solution", J. Comp. Chem. 23, p. 662 (2002).
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