Chapter 23. Parameter statements in programme GRIN

Fortran Parameter statements are used in order to define the sizes of arrays. If these array sizes need to be changed, please contact us at http://www.moldiscovery.com The Parameters, with their normal defalt values, are:

The maximum number of atoms allowed in a Recognised Molecule in datafile GRUB is 200.

The maximum number of atoms which can be processed by Programme GRIN is 24000. This limit must be large enough to contain all the atoms and hetatms in file PDB, and all the 'HYD' hydrogen atoms appended to the Target.

The maximum number of hetatms allowed in the 'HET' list at the end of datafile GRUB is 1000. It is envisaged that each user will wish to define Parameters for the hetatms that occur in the compounds which interest him. He or she may therefore want to expand the 'HET' list considerably in excess of the hetatms originally supplied with datafile GRUB. Alternatively he or she may want several different versions of GRUB, so that one version has the HET Parameters for steroids; another the Parameters for heterocycles, and so on.

The maximum number of hetero molecules which Programme GRIN can deal with is 24000. This Parameter is used when GRIN is calculating the electrostatic charge distribution in each hetero-molecule.

The maximum number of molecules which may be included in datafile GRUB is 200. This limit includes the list of HET atoms at the end of the file. i.e. 199 Recognised Molecules may be present and one 'HET' list.

The maximum number of hetatms which may be be present in an electrostatically charged chemical group such as guanidinium, when Programme GRIN calculates the delocalisation of the net eletrostatic charge over the group is 20.

The exact number of elements whose electronegativity value is available is 62. These are the basis for computing the electrostatic charge distribution in hetero-molecules.

The maximum number of hydrogen-bonding Types which may be defined is 520. Type numbers greater than 520 are not recommended.