# LRIGPW

References: Golze2017b

This section specifies optional parameters for LRIGPW. [Edit on GitHub]

## Keywords

- DEBUG_LRI_INTEGRALS

- DISTANT_PAIR_APPROXIMATION

- DISTANT_PAIR_METHOD

- DISTANT_PAIR_RADII

- EPS_O3_INT

- EXACT_1C_TERMS

- LRI_OVERLAP_MATRIX

- MAX_CONDITION_NUM

- PPL_RI

- RI_SINV

- RI_STATISTIC

- SHG_LRI_INTEGRALS

## Keyword descriptions

DEBUG_LRI_INTEGRALS: logical = F

  Lone keyword: `T`

  Usage: DEBUG_LRI_INTEGRALS TRUE

  Debug the integrals needed for LRIGPW. [Edit on GitHub]

DISTANT_PAIR_APPROXIMATION: logical = F

  Lone keyword: `T`

  Usage: DISTANT_PAIR_APPROXIMATION TRUE

  Calculate distant pairs using an independent atom approximation. [Edit on GitHub]

DISTANT_PAIR_METHOD: string = LW

  Usage: DISTANT_PAIR_METHOD {method}

  Method used to separate pair density for distant pairs. Options: EW (equal weights); AW (atomic weights); SW (set weights); LW (shell function weights) [Edit on GitHub]

DISTANT_PAIR_RADII: real[2] = 8.00000000E+000 1.20000000E+001 [bohr]

  Usage: DISTANT_PAIR_RADII r_inner {real} r_outer {real}

  Inner and outer radii used in distant pair separation. Smooth interpolation between inner and outer radius is used. [Edit on GitHub]

EPS_O3_INT: real = 1.00000000E-014

  Usage: EPS_O3_INT 1.e-10

  Threshold for ABA and ABB integrals in LRI. This is used for screening in the KS and force calculations (tensor contractions). [Edit on GitHub]

EXACT_1C_TERMS: logical = F

  Lone keyword: `T`

  Usage: EXACT_1C_TERMS TRUE

  Don’t use LRI for one center densities. [Edit on GitHub]

LRI_OVERLAP_MATRIX: enum = INVERSE

  Usage: LRI_OVERLAP_MATRIX INVERSE

  Valid values:

  - `INVERSE` Calculate inverse of the overlap matrix.

  - `PSEUDO_INVERSE_SVD` Calculate the pseuodinverse of the overlap matrix using singular value decomposition.

  - `PSEUDO_INVERSE_DIAG` Calculate the pseudoinverse of the overlap matrix by prior diagonalization.

  - `AUTOSELECT` Choose automatically for each pair whether to calculate the inverse or pseudoinverse based on the condition number of the overlap matrix for each pair. Calculating the pseudoinverse is much more expensive.

  Mentions: ⭐Local Resolution of Identity

  Specifies whether to calculate the inverse or the pseudoinverse of the overlap matrix of the auxiliary basis set. Calculating the pseudoinverse is necessary for very large auxiliary basis sets, but more expensive. Using the pseudoinverse, consistent forces are not guaranteed yet. [Edit on GitHub]

MAX_CONDITION_NUM: real = 2.00000000E+001

  Usage: MAX_CONDITION_NUM 20.0

  Mentions: ⭐Local Resolution of Identity

  If AUTOSELECT is chosen for LRI_OVERLAP_MATRIX, this keyword specifies that the pseudoinverse is calculated only if the LOG of the condition number of the lri overlap matrix is larger than the given value. [Edit on GitHub]

PPL_RI: logical = F

  Lone keyword: `T`

  Usage: PPL_RI TRUE

  Use LRI/RI for local pseudopotential. [Edit on GitHub]

RI_SINV: string = INVF

  Usage: RI_SINV NONE

  Approximation to be used for the inverse of the RI overlap matrix. INVF, INVS: exact inverse, apply directly for solver (F:full matrix, S:sparsematrix). AINV approximate inverse, use with PCG. NONE: no approximation used with CG solver. [Edit on GitHub]

RI_STATISTIC: logical = F

  Lone keyword: `T`

  Usage: RI_STATISTIC TRUE

  Print statistical information on the RI calculation. [Edit on GitHub]

SHG_LRI_INTEGRALS: logical = T

  Lone keyword: `T`

  Usage: SHG_LRI_INTEGRALS TRUE

  References: Golze2017

  Uses the SHG (solid harmonic Gaussian) integral scheme instead of Obara-Saika [Edit on GitHub]