qp_set_frozen_core¶
Automatically finds n, the number of core electrons. Calls
qp_set_mo_class setting all MOs as Active, except the
\(n/2\) first ones which are set as Core. If pseudo-potentials
are used, all the MOs are set as Active.
For elements on the right of the periodic table, qp_set_frozen_core will work as expected. But for elements on the left, a small core will be chosen. For example, a Carbon atom will have 2 core electrons, but a Lithium atom will have zero.