QuantumChemistry
MOOccupations
compute the molecular orbital (MO) occupations
Calling Sequence
Parameters
Description
Examples
MOOccupations(molecule, method, options)
molecule

list of lists; each list has 4 elements, the string of an atom's symbol and atom's x, y, and z coordinates
method
(optional) method = name/procedure where name is one of 'HartreeFock' (default), 'DensityFunctional',$\'\mathrm{ActiveSpaceCI}\'\,apos;\mathrm{ActiveSpaceSCF}apos;comma;apos;\mathrm{CoupledCluster}apos;comma;apos;\mathrm{FullCI}apos;comma;apos;\mathrm{MP2}apos;comma;apos;\mathrm{Variational2RDM}apos;comma;apos;\mathrm{Parametric2RDM}apos;comma;\phantom{\rule[0.0ex]{0.0em}{0.0ex}}\phantom{\rule[0.0ex]{0.0em}{0.0ex}}apos;\mathrm{ContractedSchrodinger}apos;$
options
(optional) equation(s) of the form option = value where option is any valid option of the chosen method
MOOccupations computes the occupations of the molecular orbitals (MOs).
The procedure returns the MO occupations as a Vector whose nth element gives the occupation of the nth MO.
The MO occupations are the eigenvalues of the oneelectron reduced density matrix (1RDM), 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.
$\mathrm{with}\left(\mathrm{QuantumChemistry}\right)\:$
Computation of the MO occupations of the $\mathrm{hydrogen}\mathrm{fluoride}\left(\mathrm{HF}\right)$ molecule with the HartreeFock method
$\mathrm{molecule}\u2254\left[\left[''H''comma;0comma;0comma;0\right]comma;\left[''F''comma;0comma;0comma;0.95\right]\right]semi;$
${\mathrm{molecule}}{\u2254}\left[\left[{''H''}{\,}{0}{\,}{0}{\,}{0}\right]{\,}\left[{''F''}{\,}{0}{\,}{0}{\,}{0.95000000}\right]\right]$
$\mathrm{output\_hf}\u2254\mathrm{MOOccupations}\left(\mathrm{molecule}comma;\mathrm{method}equals;apos;\mathrm{HartreeFock}apos;\right)semi;$
$\left[\begin{array}{c}2.00000000\\ 2.00000000\\ 2.00000000\\ 2.00000000\\ 2.00000000\\ 0.000000000\end{array}\right]$
$\phantom{\rule[0.0ex]{0.0em}{0.0ex}}\phantom{\rule[0.0ex]{0.0em}{0.0ex}}$
${}$
See Also
Energy HartreeFock DensityFunctional MP2 CoupledCluster FullCI ActiveSpaceCI ActiveSpaceSCF Variational2RDM Parametric2RDM ContractedSchrodinger
Download Help Document
What kind of issue would you like to report? (Optional)