MOOccupations computes the occupations of the molecular orbitals (MOs).

The procedure returns the MO occupations as a Vector whose n-th element gives the occupation of the n-th MO.

The MO occupations are the eigenvalues of the one-electron reduced density matrix (1-RDM), known as the natural occupations.

The default method is 'HartreeFock' method whose correlation energy is 0.

The result depends upon the chosen molecule, method, and basis set among other options such as charge, spin, and symmetry.

Because the methods employ Maple cache tables, the procedure only computes the MO occupations if they have not been previously computed by calling the method directly or indirectly through another property.

$\mathrm{with}\left(\mathrm{QuantumChemistry}\right)\:$

$\mathrm{molecule} ≔ \left[\left[''H''\,0\,0\,0\right]\,\left[''F''\,0\,0\,0.95\right]\right]\;$

$\mathrm{molecule}≔\left[\left[''H''\,0\,0\,0\right]\,\left[''F''\,0\,0\,0.95000000\right]\right]$

$\mathrm{output\_hf} ≔ \mathrm{MOOccupations}\left(\mathrm{molecule}\, \mathrm{method}\=\'\mathrm{HartreeFock}\'\right)\;$

$\mathrm{output\_hf}≔\left[\begin{array}{c}2.00000000\\ 2.00000000\\ 2.00000000\\ 2.00000000\\ 2.00000000\\ 0.\end{array}\right]$