### Overview of package pw

Real-Space and Plane-Wave Grids

- cp_linked_list_pw
- ...
- cube_utils
- for a given dr()/dh(r) this will provide the bounds to be used if one wants to go over a sphere-subregion of given radius
- dct
- the type I Discrete Cosine Transfrom (DCT-I)
- dg_rho0_types
- ...
- dg_types
- ...
- dgs
- ...
- dielectric_methods
- methods for evaluating the dielectric constant
- dielectric_types
- dielectric constant data type
- dirichlet_bc_methods
- subroutines for defining and creating Dirichlet type subdomains
- dirichlet_bc_types
- Dirichlet boundary condition data types
- fft_tools
- ...
- lazy
- Filters for interpolating scaling functions .
- lgrid_types
- Scratch space for multiple threads writing to rs grids (see qs_collocate_density.F for an example)
- mt_util
- ...
- ps_implicit_methods
- The implicit (generalized) Poisson solver
- ps_implicit_types
- Types containing essential information for running implicit (iterative) Poisson solver
- ps_wavelet_base
- Creates the wavelet kernel for the wavelet based poisson solver.
- ps_wavelet_fft3d
- ...
- ps_wavelet_kernel
- Creates the wavelet kernel for the wavelet based poisson solver.
- ps_wavelet_methods
- Definition and initialisation of the ps_wavelet data type.
- ps_wavelet_scaling_function
- Creates the wavelet kernel for the wavelet based poisson solver.
- ps_wavelet_types
- Definition and initialisation of the ps_wavelet data type.
- ps_wavelet_util
- Performs a wavelet based solution of the Poisson equation.
- pw_cuda
- ...
- pw_grid_info
- This module returns additional info on PW grids
- pw_grid_types
- ...
- pw_grids
- This module defines the grid data type and some basic operations on it
- pw_methods
- ...
- pw_poisson_methods
- ...
- pw_poisson_types
- functions related to the poisson solver on regular grids
- pw_pool_types
- Manages a pool of grids (to be used for example as tmp objects), but can also be used to instantiate grids that are never given back.
- pw_spline_utils
- different utils that are useful to manipulate splines on the regular grid of a pw
- pw_types
- ...
- realspace_grid_cube
- Generate Gaussian cube files
- realspace_grid_types
- ...
- rs_methods
- numerical operations on real-space grid