QuantumChemistry
NuclearGradient
compute the analytical nuclear gradient
Calling Sequence
Parameters
Description
Examples
NuclearGradient(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','RDMFunctional', 'ActiveSpaceCI', 'ActiveSpaceSCF', 'CoupledCluster', 'FullCI', 'MP2', 'Variational2RDM', 'Parametric2RDM'
options
(optional) equation(s) of the form option = value where option is any valid option of the chosen method
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 for all spin states of HartreeFock, DensityFunctional, and RDMFunctional as well as the singlet states of ActiveSpaceCI, ActiveSpaceSCF, CoupledCluster, FullCI, MP2, Variational2RDM, and Parametric2RDM.
On the Windows operating system the NuclearGradient command requires the installation of Microsoft's Windows Subsystem for Linux (WSL). For Windows 10 (version 2004 and higher) and Windows 11 you can install the WSL by opening the Command Prompt in administrator mode and entering the command: wsl --install -d Ubuntu For additional details, please refer to: https://learn.microsoft.com/en-us/windows/wsl/install
withQuantumChemistry:
Consider the hydrogen fluoride HF molecule
molecule ≔ H,0,0,0,F,0,0,0.95;
molecule≔H,0,0,0,F,0,0,0.95000000
The nuclear gradient of the Hartree-Fock method is
NuclearGradientmolecule, method=HartreeFock;
The nuclear gradient of the parametric 2-RDM method is
NuclearGradientmolecule, method=Parametric2RDM;
See Also
QuantumChemistry GeometryOptimization
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