# INTEGRALS

Parameters controlling how to compute integrals that are needed in MP2, RI-MP2, RI-RPA, RI-SOS-MP2 and GW (inside RI-RPA). [Edit on GitHub]

Subsections

- ERI_MME
- INTERACTION_POTENTIAL
- WFC_GPW

## Keywords

- ERI_METHOD

- SIZE_LATTICE_SUM

## Keyword descriptions

ERI_METHOD: enum = DEFAULT

  Usage: ERI_METHOD MME

  Valid values:

  - `DEFAULT` Use default ERI method (for periodic systems: GPW, for molecules: OS, for MP2 and RI-MP2: GPW in any case).

  - `GPW` Uses Gaussian Plane Wave method [DelBen2013].

  - `MME` Uses MiniMax-Ewald method (experimental, ERI_MME subsection, only for fully periodic systems with orthorhombic cells).

  - `OS` Use analytical Obara-Saika method.

  Mentions: ⭐Preliminaries

  Method for calculating periodic electron repulsion integrals (MME method is faster but experimental, forces not yet implemented). Obara-Saika (OS) for the Coulomb operator can only be used for non-periodic calculations. [Edit on GitHub]

SIZE_LATTICE_SUM: integer = 5

  Usage: SIZE_LATTICE_SUM 10

  Size of sum range L. [Edit on GitHub]