---
name: "sc_CLKS"
section: "3"
platform: "linux"
package: "libsc-doc"
version: "2.3.1-22"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/sc_CLKS"
---

# sc\_CLKS(3)

This provides a Kohn-Sham implementation for closed-shell systems.

## NAME

sc::CLKS - This provides a Kohn-Sham implementation for closed-shell systems.

## SYNOPSIS

`#include <clks.h>`

Inherits **sc::CLSCF**.

### Public Member Functions

**CLKS** (**StateIn** &)\
 **CLKS** (const **Ref**\< **KeyVal** \> &)\
 This **KeyVal** constructor reads the following keywords:  void **save\_data\_state** (**StateOut** &)\
 Save the base classes (with save\_data\_state) and the members in the same order that the **StateIn** CTOR initializes them.  void **print** (std::ostream &o=**ExEnv::out0**()) const\
 Print information about the object.  void **two\_body\_energy** (double &ec, double &ex)\
 int **value\_implemented** () const\
 Information about the availability of values, gradients, and hessians.  int **gradient\_implemented** () const\
 **RefSymmSCMatrix** **density** ()\
 Returns the **SO** density.

### Protected Member Functions

void **ao\_fock** (double accuracy)\
 double **scf\_energy** ()\
 **Ref**\< **SCExtrapData** \> **extrap\_data** ()\
 **RefSymmSCMatrix** **effective\_fock** ()\
 void **init\_vector** ()\
 void **done\_vector** ()\
 void **two\_body\_deriv** (double \*)\

### Protected Attributes

**Ref**\< **DenIntegrator** \> **integrator\_**\
 **Ref**\< **DenFunctional** \> **functional\_**\
 **RefSymmSCMatrix** **vxc\_**\
 double **exc\_**\

### Additional Inherited Members

## Detailed Description

This provides a Kohn-Sham implementation for closed-shell systems.

## Constructor & Destructor Documentation

### sc::CLKS::CLKS (const Ref\< KeyVal \> &)

This **KeyVal** constructor reads the following keywords:

- `integrator`

  Specifies the **DenIntegrator** that will be used to integrate the density functional. The default is **RadialAngularIntegrator**.

- `functional`

  Specifies the **DenFunctional** that will be used to compute the exchange/correlation contribution. This is no default.

## Member Function Documentation

### void sc::CLKS::ao\_fock (double accuracy)` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### RefSymmSCMatrix sc::CLKS::density ()` [virtual]`

Returns the **SO** density.

Implements **sc::Wavefunction**.

### void sc::CLKS::done\_vector ()` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### RefSymmSCMatrix sc::CLKS::effective\_fock ()` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### Ref\< SCExtrapData \> sc::CLKS::extrap\_data ()` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### int sc::CLKS::gradient\_implemented () const` [virtual]`

Reimplemented from **sc::Function**.

### void sc::CLKS::init\_vector ()` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### void sc::CLKS::print (std::ostream & = ExEnv::out0`()`) const` [virtual]`

Print information about the object.

Reimplemented from **sc::MolecularEnergy**.

### void sc::CLKS::save\_data\_state (StateOut &)` [virtual]`

Save the base classes (with save\_data\_state) and the members in the same order that the **StateIn** CTOR initializes them. This must be implemented by the derived class if the class has data.

Reimplemented from **sc::MolecularEnergy**.

### double sc::CLKS::scf\_energy ()` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### void sc::CLKS::two\_body\_deriv (double \*)` [protected]`, ` [virtual]`

Implements **sc::SCF**.

### void sc::CLKS::two\_body\_energy (double & ec, double & ex)` [virtual]`

Reimplemented from **sc::SCF**.

### int sc::CLKS::value\_implemented () const` [virtual]`

Information about the availability of values, gradients, and hessians.

Reimplemented from **sc::Function**.

## Author

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