# SE

Parameters needed to set up the Semi-empirical methods [Edit on GitHub]

Subsections

- COULOMB
- EXCHANGE
- GA
- LR_CORRECTION
- MEMORY
- NEIGHBOR_LISTS
- PRINT
- SCREENING

## Keywords

- ANALYTICAL_GRADIENTS

- COORDINATION_CUTOFF

- D3_SCALING

- DELTA

- DISPERSION

- DISPERSION_PARAMETER_FILE

- DISPERSION_RADIUS

- FORCE_KDSO-D_EXCHANGE

- INTEGRAL_SCREENING

- ORTHOGONAL_BASIS

- PERIODIC

- STO_NG

## Keyword descriptions

ANALYTICAL_GRADIENTS: logical = T

  Lone keyword: `T`

  Usage: ANALYTICAL_GRADIENTS

  Nuclear Gradients are computed analytically or numerically [Edit on GitHub]

COORDINATION_CUTOFF: real = 1.00000000E-006

  Usage: COORDINATION_CUTOFF

  Define cutoff for coordination number calculation [Edit on GitHub]

D3_SCALING: real[3] = 0.00000000E+000 0.00000000E+000 0.00000000E+000

  Usage: D3_SCALING 1.0 1.0 1.0

  Scaling parameters (s6,sr6,s8) for the D3 dispersion method, [Edit on GitHub]

DELTA: real = 1.00000000E-006

  Usage: DELTA {real}

  Step size in finite difference force calculation [Edit on GitHub]

DISPERSION: logical = F

  Lone keyword: `T`

  Usage: DISPERSION

  Use dispersion correction [Edit on GitHub]

DISPERSION_PARAMETER_FILE: string

  Usage: DISPERSION_PARAMETER_FILE filename

  Specify file that contains the atomic dispersion parameters [Edit on GitHub]

DISPERSION_RADIUS: real = 1.50000000E+001

  Usage: DISPERSION_RADIUS

  Define radius of dispersion interaction [Edit on GitHub]

FORCE_KDSO_D_EXCHANGE: logical = F

  Lone keyword: `T`

  This keywords forces the usage of the KDSO-D integral screening for the Exchange integrals (default is to apply the screening only to the Coulomb integrals. [Edit on GitHub]

INTEGRAL_SCREENING: enum = KDSO

  Usage: INTEGRAL_SCREENING (KDSO|KDSO-D|SLATER)

  Valid values:

  - `KDSO` Uses the standard NDDO Klopman-Dewar-Sabelli-Ohno equation for the screening of the Coulomb interactions.

  - `KDSO-D` Uses a modified Klopman-Dewar-Sabelli-Ohno equation, dumping the screening parameter for the Coulomb interactions.

  - `SLATER` Uses an exponential Slater-type function for modelling the Coulomb interactions.

  Specifies the functional form for the [Edit on GitHub]

ORTHOGONAL_BASIS: logical = F

  Lone keyword: `T`

  Usage: ORTHOGONAL_BASIS

  Assume orthogonal basis set. This flag is overwritten by methods with fixed orthogonal/non-orthogonal basis set. [Edit on GitHub]

PERIODIC: enum = NONE

  Usage: PERIODIC (NONE|EWALD|EWALD_R3|EWALD_GKS)

  Valid values:

  - `NONE` The long-range part is not explicitly treaten. The interaction depends uniquely on the Cutoffs used for the calculation.

  - `EWALD` Enables the usage of Multipoles Ewald summation schemes. The short-range part is tapered according the value of RC_COULOMB.

  - `EWALD_R3` Enables the usage of Multipoles Ewald summation schemes together with a long-range treatment for the 1/R^3 term, deriving from the short-range component. This option is active only for K-DSO integral screening type.

  - `EWALD_GKS` Use Ewald directly in Coulomb integral evaluation, works only with Slater screening

  Specifies the type of treatment for the electrostatic long-range part in semi-empirical calculations. [Edit on GitHub]

STO_NG: integer = 6

  Usage: STO_NG

  Provides the order of the Slater orbital expansion of Gaussian-Type Orbitals. [Edit on GitHub]