CCL: Computation Resource Requirement.

[Pijush Ghosh <pijush.ghosh~at~ndsu.nodak.edu>]

 CCL Users,
      being new to the field of computational quantum mechanics, i
 have
 a basic question on the requirement of the resources for this type of
 computation.  Can anybody  cite any reference where i can get some
 relation between number of processors and time required  with that of
 number of atoms in a system , basis set used, etc.
 
 In my system of Hydroxyapatite- polymer I have the following details:
 atom                 number
 Calcium              20
 Phosphorous      12
 Oxygen              54
 Hydrogen           10
 Carbon                 3
 Basis set -            6-31+G**
 Method -              HF (Hartree Fock)
can somebody  give idea on  processor-hour required. All my
 simulations
 are run on NCSA machines.
 All suggesions and information appreciated in advance.
 Pijush Ghosh.
 NDSU.