The NuclearGradient command computes the analytical nuclear gradient if available.

The output is a 3×N matrix where N is the number of atoms in the molecule.

Analytical nuclear gradients are implemented on the MacOS X and Linux platforms for all spin states of HartreeFock and DensityFunctional as well as the singlet states of ActiveSpaceCI, ActiveSpaceSCF, CoupledCluster, FullCI, MP2, Variational2RDM, and Parametric2RDM.

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

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

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

$\mathrm{NuclearGradient}\left(\mathrm{molecule}\, \mathrm{method}\=\mathrm{HartreeFock}\right)\;$

$\left[\begin{array}{ccc}0.000000000& 0.000000000& 0.00760801105\\ 0.000000000& 0.000000000& -0.00760801105\end{array}\right]$

$\mathrm{NuclearGradient}\left(\mathrm{molecule}\, \mathrm{method}\=\mathrm{Parametric2RDM}\right)\;$

$\left[\begin{array}{ccc}0.000000000& 0.000000000& 0.0510196860\\ 0.000000000& 0.000000000& -0.0510196860\end{array}\right]$