Density based Cavity Construction:

Instead of using atom specific radii the cavity can be defined by the electron density. In such an isodensity cavity construction one can use the same density value for all atoms types or the so-called scaled isodensity values. In the later approach different densities are used for the different atom types. The algorithm implemented in TURBOMOLE uses a marching tetrahedron algorithm for the density based cavity construction. In order to assure a smooth density change in the intersection seams of atoms with different isodensity specification, this areas are smoothend by a radii based procedure.