RI
Parameters for RI methods in HFX, including RI-HFXk with k-point sampling. All keywords relevant to RI-HFXk have an alias starting with KP_ [Edit on GitHub]
Subsections
Keywords
Keyword descriptions
- SECTION_PARAMETERS
Type: logical
Default: F
Lone keyword: T
Usage: &RI TDescription: controls the activation of RI
- 2C_MATRIX_FUNCTIONS
Type: enum
Default: CHOLESKYDescription: Methods for matrix inverse and matrix square root.
Valid values:
DIAGDiagonalization with eigenvalue quenching: stableCHOLESKYCholesky: not stable in case of ill-conditioned RI basisITERIterative algorithms: linear scaling Hotelling’s method for inverse and Newton-Schulz iteration for matrix square root
- CALC_COND_NUM
Type: logical
Default: F
Aliases: CALC_CONDITION_NUMBER
Lone keyword: T
Usage: CALC_COND_NUMDescription: Calculate the condition number of integral matrices.
- CHECK_2C_MATRIX
Type: logical
Default: F
Lone keyword: TDescription: Report accuracy for the inverse/sqrt of the 2-center integral matrix.
- CUTOFF_RADIUS
Type: real
Default: 0.00000000E+000 [angstrom]
Aliases: KP_CUTOFF_RADIUSDescription: The cutoff radius (in Angstroms) for the truncated Coulomb operator. Default is CUTOFF_RADIUS from INTERACTION_POTENTIAL.
- EPS_EIGVAL
Type: real
Default: 1.00000000E-007Description: Throw away linear combinations of RI basis functions with a small eigenvalue, this is applied only if 2C_MATRIX_FUNCTIONS DIAG
- EPS_FILTER
Type: real
Default: 1.00000000E-009
Aliases: KP_EPS_FILTERDescription: Filter threshold for DBT tensor contraction.
- EPS_FILTER_2C
Type: real
Default: 1.00000000E-012Description: Filter threshold for 2c integrals. Default should be kept.
- EPS_FILTER_MO
Type: real
Default: 1.00000000E-012Description: Filter threshold for contraction of 3-center integrals with MOs. Default should be kept.
- EPS_LANCZOS
Type: real
Default: 1.00000000E-003Description: Threshold used for lanczos estimates.
- EPS_PGF_ORB
Type: real
Default: 1.00000000E-005
Aliases: KP_EPS_PGF_ORBDescription: Sets precision of the integral tensors.
- EPS_STORAGE_SCALING
Type: real
Default: 1.00000000E-002Description: Scaling factor to scale EPS_FILTER for storage of 3-center integrals. Storage threshold will be EPS_FILTER*EPS_STORAGE_SCALING.
- FLAVOR_SWITCH_MEMORY_CUT
Type: integer
Default: 3Description: Memory reduction factor to be applied upon RI_FLAVOR switching from MO to RHO. The RHO flavor typically requires more memory, and depending on the ressources available, a higher MEMORY_CUT.
- KP_NGROUPS
Type: integer
Default: 1
Aliases: NGROUPS
Usage: KP_NGROUPS {int}Description: The number of MPI subgroup that work in parallel during the SCF. The default value is 1. Using N subgroups should speed up the calculation by a factor ~N, at the cost of N times more memory usage.
- KP_RI_BUMP_FACTOR
Type: real
Default: 8.50000000E-001
Aliases: RI_BUMP, BUMP, BUMP_FACTORDescription: In KP-RI-HFX, the extended RI basis set has a bump radius. All basis elements within that radius contribute with full weight. All basis elements beyond that radius have decaying weight, from 1 at the bump radius, to zero at the RI extension radius. The bump radius is calculated as a fraction of the RI extension radius: bump radius = KP_RI_NUMP_FACTOR * RI extension radius
- KP_STACK_SIZE
Type: integer
Default: 16
Aliases: STACK_SIZE
Usage: KP_STACK_SIZE {int}Description: When doing contraction over periodic cells of the type: T_mu^a,nu^b,P^c = (mu^a nu^b | Q^d) * (Q^d | P^c), with a,b,c,d labeling cells, there are in principle Ncells contractions taking place. Because a smaller number of contractions involving larger tensors is more efficient, the tensors can be stacked along the d direction. STCK_SIZE controls the size of this stack. Larger stacks are more efficient, but required more memory.
- KP_USE_DELTA_P
Type: logical
Default: T
Aliases: USE_DELTA_P, KP_USE_P_DIFF, USE_P_DIFF
Usage: KP_USE_DELTA_P {logical}Description: This kweyword controls whether the KS matrix at each SCF cycle is built by adding the contribution of the denisty difference (wrt to previous step) to the KS matrix of the previous step. As the SCF converges, the density fluctuations get smaller and sparsity increases, leading to faster SCF steps. Not always numerically stable => turn off if SCF struggles to converge.
- MAX_BLOCK_SIZE_MO
Type: integer
Default: 64Description: Maximum tensor block size for MOs.
- MAX_ITER_LANCZOS
Type: integer
Default: 500
Usage: MAX_ITER_LANCZOSDescription: Maximum number of lanczos iterations.
- MEMORY_CUT
Type: integer
Default: 3Description: Memory reduction factor. This keyword controls the batching of tensor contractions into smaller, more manageable chunks. The details vary depending on the RI_FLAVOR.
- MIN_BLOCK_SIZE
Type: integer
Default: 4Description: Minimum tensor block size.
- OMEGA
Type: real
Default: 0.00000000E+000
Aliases: KP_OMEGADescription: The range parameter for the short range operator (in 1/a0). Default is OMEGA from INTERACTION_POTENTIAL.
- RI_FLAVOR
Type: enum
Default: RHODescription: Flavor of RI: how to contract 3-center integrals
Valid values:
MOwith MO coefficientsRHOwith density matrix
- RI_METRIC
Type: enum
Default: HFX
Aliases: KP_RI_METRIC
Usage: RI_METRIC {string}Description: The type of RI operator. Default is POTENTIAL_TYPE from INTERACTION_POTENTIAL. The standard Coulomb operator cannot be used in periodic systems.
Valid values:
HFXSame as HFX operatorCOULOMBStandard Coulomb operator: 1/rIDENTITYOverlapTRUNCATEDTruncated Coulomb operator: 1/r if (r<R_c), 0 otherwiseSHORTRANGEShort range: erfc(omega*r)/r
- SCALE_COULOMB
Type: real
Default: 1.00000000E+000
Usage: SCALE_COULOMB 1.0Description: Scales Hartree-Fock contribution arising from a coulomb potential. Only valid when doing a mixed potential calculation. Default is SCALE_COULOMB from INTERACTION_POTENTIAL
- SCALE_LONGRANGE
Type: real
Default: 1.00000000E+000
Usage: SCALE_LONGRANGE 1.0Description: Scales Hartree-Fock contribution arising from a longrange potential. Only valid when doing a mixed potential calculation. Default if SCALE_LONGRANGE from INTERACTION_POTENTIAL
- SQRT_ORDER
Type: integer
Default: 3Description: Order of the iteration method for the calculation of the sqrt of 2-center integral matrix.