Using Gaussian98
b3pw91/6-311g(d) scf=direct fopt

Optimized Structure

-2.207322   -3.133836    0.011773
 3.243202    0.000000    2.223951
-1.560258    0.000000   -1.976543
-0.754285    0.000000    1.623309
 4.853129    0.000000   -1.110275
 1.517512    1.923398   -0.598273
 1.517513   -1.923397   -0.598273
-2.207324    3.133837    0.011774
-4.402167    0.000000    0.412557

                    Distance matrix (angstroms):
                    1          2          3          4          5
     1  Ca   0.000000
     2  Ca   6.665048   0.000000
     3  Ca   3.767362   6.381017   0.000000
     4  Ca   3.811730   4.042360   3.688974   0.000000
     5  Ca   7.805760   3.702557   6.471627   6.238235   0.000000
     6  Ca   6.310480   3.826541   3.882237   3.714290   3.884320
     7  Ca   3.963800   3.826540   3.882236   3.714290   3.884320
     8  Ca   6.267673   6.665050   3.767364   3.811732   7.805761
     9  Ca   3.846934   7.857023   3.712714   3.843560   9.379739
                    6          7          8          9
     6  Ca   0.000000
     7  Ca   3.846795   0.000000
     8  Ca   3.963801   6.310482   0.000000
     9  Ca   6.305857   6.305857   3.846934   0.000000

SCF Done:  E(RB+HF-PW91) =  -6097.80571861 au

E(9 atoms of Calcium) = -6097.588045 au

Binding Energy = 5.9232 ev (0.6581 ev/atom)