Sparse representation

We have analyzed three big systems for sparse representation, the biggest one is the triad surrounded by water molecules that Carlos is working on:
It contains 666 atoms, the hamiltonian and overlapr matrices are 7792 X 7792 stored as an array of 30361528 elements. Of these only 800842 are non zero for the hamiltonian matrix and 930451 for the overlap matrix. The condition for sparse representation using the Yale format is satisfied.
The other system is just the triad
Atoms=207
N=6157
N_tot=18957403
HAM
Non Zero=1906717
OVL
Non Zero=2216039
The last one was the SC3N@C80-ZnTPP
Atoms=161
N=5231
N_tot=13684296
HAM
Non Zero=2867932
OVL
Non Zero=3251155
With this last one the total size of HAMOLD was 109474392 bytes while the total size of the sparse representation (the data array and the two auxiliary arrays) was: 34436172 bytes