Isodensity Cavity:

This option can be used in HF/DFT single point calculations only. The $cosmo_isodens section defines the settings for the density based cavity setup (see also chapter 14). If the $cosmo_isodens keyword is given without suboptions, a scaled iosodensity cavity with default settings will be created. Possible options are:

$cosmo_isodens

activates the density based cavity setup. The default values of nspa and nsph are changed to 162 and 92, respectively. This values are superseded by the user defined nspa value of the $cosmo section. By default the scaled density method is used. The atom type dependent density values are read from the radii.cosmo file (located in $TURBODIR/parameter).

dx=real

spacing of the marching tetrahedron grid in Å (defualt: 0.3Å).

all_dens=real

use one isodensity value for all atom types (value in a.u.)

The outlying charge correction will be performed with a radii based outer cavity. Therfore, and for the smoothing of the density changes in the intersection areas of the scaled density method, radii are needed as for the standard COSMO cavity. Please note: The isodensity cavity will be contructed only once at the beginnig of the SCF calculation. The density contructed from the initial mos will be used (file mos or alpha/beta in case of unrestricted calculations). Because the mos of an initial guess do not provide a good density for the cavity construction, it is necessary to provide mos of a converged SCF calculation (e.g. a COSMO calculation with standard cavity). We recommend the following three steps: perform a standard COSMO calculation, add the isodensity options afterwards, and start the calculation a second time.