Grids#
Type of grids#
- Two type of grids are used throughout rgmol :
the calculation grid
the representation grid
The grids will be automatically created using the plotting and calculation methods using optimized parameters. But if one wants to change the parameters, the following part will explain how to.
Calculation Grids#
Calculation grids or atomic grids are the grids used for computation of new properties. Typically they are used for the computation of the eigenmodes of kernels.
The calculations grids are multi-center grids around each atom. The Becke scheme [1] is used to integrate properly each grid. The radial formula used is Treutler and Ahlrichs’ M4 formula [2] The angular part is using the Lebedev quadrature [3]
All the parameters were optimized for each atom by integrating each atomic orbital without normalization, and getting results with an accuracy of at least 1e-9
This grid can be visualized using the plot_atomic_grid method. And any vector can be visualized on this grid using the plot_on_atomic_grid method.
On can also use its own parameters using create_grid_from_mol and create_atomic_grid.
Integration#
In order to integrate on atomic grids, one can get the atomic grids using molecule.mol_grids Then the methods that can be used are
Representation Grid#
The representation grid is a simple cubic grid that is defined around the molecule. This grid is used to represent the vectors and is not used for calculation, only visualization.
One can use the grid_points and delta parameters of all the plotting methods to shape this grid as intended.