Example:

The $4d^5 5s^1$ $^7$S state of Mo, treated in symmetry I

$roothaan         1
  a = 1      b = 2
$closed shells
  a      1-4                                    ( 2 )
  t1     1-3                                    ( 2 )
  h      1                                      ( 2 )
$open shells type=1
  a      5                                      ( 1 )
  h      2                                      ( 1 )