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

# sc\_SpatialMOPairIter(3)

SpatialMOPairIter gives the ordering of pairs of spatial orbitals.

## NAME

sc::SpatialMOPairIter - **SpatialMOPairIter** gives the ordering of pairs of spatial orbitals.

## SYNOPSIS

`#include <pairiter.h>`

Inherits **sc::MOPairIter**.

Inherited by **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

### Public Member Functions

**SpatialMOPairIter** (const **Ref**\< **MOIndexSpace** \> &space\_i, const **Ref**\< **MOIndexSpace** \> &space\_j)\
 Initialize a spatial pair iterator for the given MO spaces.  virtual int **nij\_aa** () const =0\
 Returns the number of functions in alpha-alpha space.  virtual int **nij\_ab** () const =0\
 Returns the number of functions in alpha-beta space.  virtual int **ij\_aa** () const =0\
 Returns compound index ij for alpha-alpha case.  virtual int **ij\_ab** () const =0\
 Returns compound index ij for alpha-beta case.  virtual int **ij\_ba** () const =0\
 Returns compound index ij for beta-alpha case.

### Additional Inherited Members

## Detailed Description

**SpatialMOPairIter** gives the ordering of pairs of spatial orbitals.

Different spin cases appear.

## Member Function Documentation

### virtual int sc::SpatialMOPairIter::ij\_aa () const` [pure virtual]`

Returns compound index ij for alpha-alpha case. If the combintaion is not allowed then return -1

Implemented in **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

### virtual int sc::SpatialMOPairIter::ij\_ab () const` [pure virtual]`

Returns compound index ij for alpha-beta case.

Implemented in **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

### virtual int sc::SpatialMOPairIter::ij\_ba () const` [pure virtual]`

Returns compound index ij for beta-alpha case.

Implemented in **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

### virtual int sc::SpatialMOPairIter::nij\_aa () const` [pure virtual]`

Returns the number of functions in alpha-alpha space.

Implemented in **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

### virtual int sc::SpatialMOPairIter::nij\_ab () const` [pure virtual]`

Returns the number of functions in alpha-beta space.

Implemented in **sc::SpatialMOPairIter\_eq**, and **sc::SpatialMOPairIter\_neq**.

## Author

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