RI_RS
Real-Space Resolution of Identity (RI-RS) method. This approximation replaces the conventional 3-center RI integrals \((\mu\nu|P)\) by a factorized representation on an atom-centered real-space grid with points \(\mathbf{r}_\ell\): \((\mu\nu|P) \approx \sum_\ell \varphi_\mu(\mathbf{r}_\ell) \varphi_\nu(\mathbf{r}_\ell) Z_{\ell P}\). The coefficients \(Z_{\ell P}\) combine the numerical integration weights and the Coulomb potential of the auxiliary basis function \(P\) evaluated at grid point \(\mathbf{r}_\ell\). To reduce the computational cost, only grid points within the sphere \(B^P\) around atom \(P\) are included, i.e. the points with \(|\mathbf{r}_\ell - \mathbf{R}_P| < R_c + r_P\). Here, \(r_P\) is the effective radius of the most diffuse RI auxiliary Gaussian on atom \(P\), at which the basis function magnitude falls below a threshold \(\delta\) (currently controlled through EPS_FILTER). This locality approximation yields a sparse representation of the 3-center integrals and enables reduced computational cost. See details in https://doi.org/10.1063/1.5090605. [Edit on GitHub]
Subsections
Keywords
Keyword descriptions
- SECTION_PARAMETERS
Type: logical
Default: F
Lone keyword: T
Usage: &RI_RS .TRUE.Description: Controls the activation of RI-RS in the GW calculation. An empty section, &RI_RS … &END RI_RS, switches RI-RS on with default parameters. [Edit on GitHub]
- CUTOFF_RADIUS_G_W
Type: real
Default: -1.00000000E+000 [angstrom]
Usage: CUTOFF_RADIUS_G_W 20.0Description: Atom-pair distance truncation radius (Angstrom) applied to the AO/RI-space operator matrices G, D, V and W themselves in the RI-RS GW contractions: matrix blocks between atoms further apart than this radius are dropped. Physically consistent with CUTOFF_RADIUS_RL_W, which truncates the grid-basis products at the same kind of range. Default -1.0 disables the truncation (exact operators). [Edit on GitHub]
- CUTOFF_RADIUS_RL_AO
Type: real
Default: -1.00000000E+000 [angstrom]
Usage: CUTOFF_RADIUS_RL_AO 8.0Description: Real-space cutoff radius (in Angstrom) for evaluating the AO basis functions on the RI-RS grid. Override the default radius derived automatically from the most diffuse AO Gaussian on each atom. [Edit on GitHub]
- CUTOFF_RADIUS_RL_RI
Type: real
Default: -1.00000000E+000 [angstrom]
Usage: CUTOFF_RADIUS_RL_RI 15.0Description: Real-space cutoff radius (in Angstrom) for evaluating the RI-RS integration domain \(B^P\). Overrides the default \(R_c + r_P\), where \(R_c\) is the truncated-Coulomb cutoff of the RI metric and \(r_P\) the radius of the most diffuse RI auxiliary Gaussian on atom \(P\). [Edit on GitHub]
- CUTOFF_RADIUS_RL_W
Type: real
Default: -1.00000000E+000 [angstrom]
Usage: CUTOFF_RADIUS_RL_W 20.0Description: Real-space truncation radius (Angstrom) for the grid-basis G operators in the RI-RS GW self-energy. Default -1.0 disables the truncation (exact grid-basis operators). [Edit on GitHub]
- GRID_FILE_SUFFIX
Type: string
Usage: _GRID_FILE_SUFFIX my-grids.ionDescription: Overrides the per-element grid file suffix used by GRID_SELECT 3; grid files are read as ri_rs_grid/
. [Edit on GitHub]
- GRID_SELECT
Type: integer
Default: 1
Usage: GRID_SELECT 1Description: Selection of the atom-centered grid type used in RI-RS optimized by Duchemin and Blase. (1) def2-TZVPP: Available for elements up to the fourth row of the periodic table (see https://doi.org/10.1021/acs.jctc.1c00101). (2) cc-pVTZ: Available for H, C, N, and O atoms (see https://doi.org/10.1063/1.5090605). (3) User-provided grids: per-element grid files supplied by the user, read as ri_rs_grid/
in the same format as the built-in sets; the suffix is _rirs.ion by default and can be changed with GRID_FILE_SUFFIX. [Edit on GitHub]
- KEEP_SPARSITY_RL
Type: logical
Default: T
Usage: KEEP_SPARSITY_RL .FALSE.Description: If
.TRUE.(default), the W/V matrices in the grid-basis contractions of RI-RSwill used the sparsity pattern of the corresponding G/D matrices. Set.FALSE.to build W/V fully dense. [Edit on GitHub]
- N_PANELS
Type: integer
Default: 1
Usage: N_PANELS 4Description: Number of grid panels (batches) the real-space grid is split into for the streaming chi/W/Sigma contractions in RI-RS. More panels means lower peak memory per step but more overhead. Default 1 = a single whole-grid panel. On large cells the number of panels is automatically increased beyond the request to keep per-rank DBCSR messages under the 32-bit length limit. [Edit on GitHub]
- N_PROCS_PER_ATOM_Z_LP
Type: integer
Default: -1
Usage: N_PROCS_PER_ATOM_Z_LP 2Description: Number of MPI ranks that cooperate on one atom’s Cholesky factorisation in computation of \(Z_{\ell P}\) in RI-RS. Default -1 = AUTO: each atom is solved single-rank (fast BLAS) unless its dense grid-overlap matrix would exceed the available memory per process, in which case it is distributed across a rank subgroup sized automatically (ScaLAPACK). Set to 1 to force single-rank for all atoms, or > 1 to force that fixed subgroup size for all atoms. [Edit on GitHub]
- TIKHONOV
Type: real
Default: 1.00000000E-008
Usage: TIKHONOV 1.0E-8Description: Regularization parameter \(\alpha\) used to stabilize the inversion of the grid-overlap matrix \(D\) in the RI-RS method. See Equation (9) in https://doi.org/10.1063/1.5090605. [Edit on GitHub]