Gaussian98
#b3pw91/6-311g(d) scf=(direct,dsymm,symm) symm=loose fopt

Optimized Structure

0.000000    0.000000   -2.134497
0.000000    0.000000    2.134497

Distance

R(1,2)                  4.269

SCF Done:  E(RB+HF-PW91) =  -1355.02496234

E(2 atoms of Calcium) = -1355.019566

Energy =    0.1468 ev (0.0734 ev/atom)

Single-Point Energy
b3pw91/6-311+g(df)
9.5 minutes
-1355.025058 hartees
B.E. = 0.0739366