# ERI

Parameters for the electron repulsion integrals. [Edit on GitHub]

## Keywords

- CUTOFF_RADIUS

- EPS_INTEGRAL

- METHOD

- OPERATOR

- OPERATOR_PARAMETER

- PERIODICITY

## Keyword descriptions

CUTOFF_RADIUS: real = -1.00000000E+000

  Usage: CUTOFF_RADIUS 20

  Radius of operator interactions in non-periodic cases. [Edit on GitHub]

EPS_INTEGRAL: real = 1.00000000E-012

  Usage: EPS_INTEGRAL 1.0E-10

  Accuracy of ERIs that will be stored. [Edit on GitHub]

METHOD: enum = FULL_GPW

  Usage: METHOD FULL_GPW

  Valid values:

  - `FULL_GPW` Use the GPW approach with MOs

  - `GPW_HALF_TRANSFORM` Use the GPW approach for half-transformed MO ERIs

  Method used in ERI calculation. [Edit on GitHub]

OPERATOR: enum = <1/R>

  Usage: OPERATOR <1/R>

  Valid values:

  - `<1/R>` Coulomb operator

  - `<EXP(-A*R)/R>` Yukawa potential operator

  - `<ERF(A*R)/R>` Error function potential operator

  - `<ERFC(A*R)/R>` Complementary error function potential operator

  - `<EXP(-A*R2)/R>` Gaussian potential operator

  - `<H(A-R)/R>` Truncated Coulomb potential

  Operator used in ERI calculation. [Edit on GitHub]

OPERATOR_PARAMETER: real = 5.00000000E-001

  Usage: OPERATOR_PARAMETER 4.0

  Range parameter for ERI operator. [Edit on GitHub]

PERIODICITY: integer[ ] = 1 1 1

  Usage: PERIODICITY {1 1 1}

  Periodicity used for operators in ERI calclulation. [Edit on GitHub]