The SCRF input is contained in an SCRF input block as shown below, optional keywords being surrounded by curly brackets.
SCRF MEADGRID string integer real RADIUS string real {BLAB integer} {CYCLES integer} {TOLERANCE real} {ATOM_MAXR real} {CHGFIT_CONSTRAIN string} {DELATOM integer} {GRID_SPACING real} {SVD_CONDITION real} {SV_DELETE integer} {EPSSOL real} {IONIC_STR real} {SOLRAD real} END
The SCRF block contains two mandatory keys: MEADGRID and RADIUS. All other keys are optional.
MEADGRID string integer real
Specifies the centering style, dimension and spacing for the MEAD grid. Recognized centering styles are "ON_ORIGIN" and "ON_GEOM_CENT". The grid dimension specifies the number of points on one edge of a cubic grid. The grid spacing is given in Angstroms. The edge length of the grid is the product of the dimension minus 1 and the spacing. Multiple records may be used to specify sequentially finer grid levels, but finer grids must fit within the coarsest grid.
RADIUS string real
Specifies the radius in Angstroms for an atom type. Used in fitting the ADF electronic structure to partial atomic charges and for defining the boundary between regions of low and high dielectric in MEAD. The atom types should be the same as those used in the ATOMS input block. There must be one RADIUS record for each atom type in the ATOMS input block.
BLAB integer
Specifies the level of detail in the stdout for the SCRF process. BLAB level may be set at 1, 2 or 3. BLAB level = 3 gives the most detail and BLAB level = 1 gives the least. Defaults to 1.
CYCLES integer
Specifies the maximum number of cycles of SCRF to perform. Whether or not the SCRF run has converged, it will terminate when the number of cycles exceeds the value specified by CYCLES.
TOLERANCE real
Specifies convergence criterion in kcal/mol for SCRF. For each cycle of SCRF the sum of ADF energy, reaction energy, the energy correction and nuclear reaction energy is calculated. If the difference in subsequent sums is less than the TOLERANCE value, SCRF is considered to have converged. Defaults to 0.01.
ATOM_MAXR real
Specifies the outer atomic radius in Angstroms for the system. For each atom, grid points that lie between the atomic radius specified by the RADIUS keyword and the outer atomic radius specified here are included in charge fitting. Defaults to 5.0.
CHGFIT_CONSTRAIN string
Specifies the type of constraints to be used in charge fitting. Recognized constraints are "NONE", "CHARGE" or "DIPOLE". NONE specifies no constraints will be applied, CHARGE specifies that only the molecular charge will be constrained and DIPOLE specifies that both the molecular charge and dipole will be constrained. Default is DIPOLE.
DELATOM integer
Specifies which atoms should be excluded from the charge fitting procedure. The input order in the ATOMS input block is used to identify the excluded atom. Multiple DELATOM records may be declared and will be applied cumulatively. The default is to include all atoms.
GRID_SPACING real
Specifies the grid spacing in Angstroms for the charge fitting grid. The default is 0.2.
SVD_CONDITION real
Specifies a condition number threshold for inclusion of singular values (SV) in singular value decomposition (SVD) during charge fitting. The default is 0.000001.
SV_DELETE integer
Instead of using a condition number threshold for deciding which SV to include in charge fitting, SV_DELETE may be used to specify how many SV should be excluded. The smallest SV are excluded first. The default is to use a condition number threshold. If both SV_DELETE and SVD_CONDITION are specified, the SV_DELETE value will take precedence.
EPSSOL real
Specifies the solvent dielectric for MEAD. Defaults to the dielectric of water: 80.0.
IONIC_STR real
Specifies an ionic strength in mol/L for the solvent in MEAD. Defaults to 0.0.
SOLRAD real
Specifies the radius in Angstroms of a solvent-sized probe that rolls along the surface of the molecular system to define the dielectric boundary. Defaults to a water-sized probe size of 1.4.
