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

# sc\_MOIndexSpace(3)

Class MOIndexSpace describes a range of molecular orbitals or similar objects that are linear combinations of basis functions (e.g.

## NAME

sc::MOIndexSpace - Class **MOIndexSpace** describes a range of molecular orbitals or similar objects that are linear combinations of basis functions (e.g.

## SYNOPSIS

`#include <moindexspace.h>`

Inherits **sc::SavableState**.

### Public Types

enum **IndexOrder** { **symmetry** = 0, **energy** = 1, **undefined** = 2 }\
 Describes the ordering of indices.

### Public Member Functions

**MOIndexSpace** (**StateIn** &)\
 **MOIndexSpace** (std::string **name**, const **RefSCMatrix** &full\_coefs, const **Ref**\< **GaussianBasisSet** \> **basis**, const **Ref**\< **Integral** \> &**integral**, const vector\< int \> &**offsets**, const vector\< int \> &nmopi, **IndexOrder** **moorder**=symmetry, const **RefDiagSCMatrix** &**evals**=0)\
 This function constructs an **MOIndexSpace** from (blocked) space full\_coefs.  **MOIndexSpace** (std::string **name**, const **RefSCMatrix** &full\_coefs, const **Ref**\< **GaussianBasisSet** \> **basis**, const **Ref**\< **Integral** \> &**integral**, const **RefDiagSCMatrix** &**evals**, int nfzc, int nfzv, **IndexOrder** **moorder**=energy)\
 This constructor should be used when the **MOIndexSpace** object is a subspace of a full orbital space.  **MOIndexSpace** (std::string **name**, const **RefSCMatrix** &full\_coefs, const **Ref**\< **GaussianBasisSet** \> **basis**, const **Ref**\< **Integral** \> &**integral**)\
 This constructor should be used when the **MOIndexSpace** object is the full orbital space.  **MOIndexSpace** (std::string **name**, const **Ref**\< **MOIndexSpace** \> &orig\_space, const **RefSCMatrix** &new\_coefs, const **Ref**\< **GaussianBasisSet** \> &new\_basis)\
 This constructor is a true hack introduced because I have no idea how to construct what I need.  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.  const std::string **name** () const\
 Returns the name of this **MOIndexSpace**.  const **Ref**\< **GaussianBasisSet** \> **basis** () const\
 Returns the AO basis set.  **Ref**\< **Integral** \> **integral** () const\
 Returns the integral factory used to instantiate the coefficient matrix.  const **RefSCMatrix** **coefs** () const\
 Returns the coefficient matrix.  const **RefDiagSCMatrix** **evals** () const\
 Returns the 'eigenvalues' matrix.  vector\< int \> **mosym** () const\
 Returns the orbital symmetry array.  **IndexOrder** **moorder** () const\
 Returns the order of the orbitals.  int **rank** () const\
 Returns the rank of the space.  int **full\_rank** () const\
 Returns the rank of the full space.  int **nblocks** () const\
 Returns the number of blocks.  vector\< int \> **nmo** () const\
 Returns the number of orbitals in each block.  vector\< int \> **offsets** () const\
 Returns the full-space index of the first orbital in each block.  int **to\_full\_space** (const int i) const\
 Returns the full-space index.  size\_t **memory\_in\_use** () const\
 Returns how much 'significant' (i.e. O^2) memory this object uses.  void **print** (std::ostream &o=**ExEnv::out0**()) const\
 Prints out this.  void **print\_summary** (std::ostream &os) const\
 Produces a short summary.

### Additional Inherited Members

## Detailed Description

Class **MOIndexSpace** describes a range of molecular orbitals or similar objects that are linear combinations of basis functions (e.g.

atomic orbitals). In general, such sets are subspaces of a full space of orbitals supported by the given basis. Orbitals can be symmetry-blocked, ordered by energy, etc. Examples of sets that can be described using **MOIndexSpace** are occupied MOs and virtual MOs.

## Constructor & Destructor Documentation

### sc::MOIndexSpace::MOIndexSpace (std::string name, const RefSCMatrix & full\_coefs, const Ref\< GaussianBasisSet \> basis, const Ref\< Integral \> & integral, const vector\< int \> & offsets, const vector\< int \> & nmopi, IndexOrder moorder = `symmetry`, const RefDiagSCMatrix & evals = `0`)

This function constructs an **MOIndexSpace** from (blocked) space full\_coefs. Block i will contain vectors \[ offsets\[i\], offsets\[i\]+nmopi\[i\]-1 \] . By default, the space maintains the same blocked structure and the same order within blocks as the original space (moorder=symmetry). If moorder=energy and eigenvalues evals are provided, then all vectors will be put in one block and sorted according to ascending evals.

**Parameters**

*name* -- the name of this **MOIndexSpace** \
 *full\_coefs* -- symmetry-blocked transformation coefficient matrix (AO by MO) for the full space \
 *basis* -- basis set \
 *integral* -- integral factory \
 *offsets* -- block offsets \
 *nmopi* -- new block sizes \
 *moorder* -- specifies new ordering of vectors \
 *evals* -- used to sort the vectors

### sc::MOIndexSpace::MOIndexSpace (std::string name, const RefSCMatrix & full\_coefs, const Ref\< GaussianBasisSet \> basis, const Ref\< Integral \> & integral, const RefDiagSCMatrix & evals, int nfzc, int nfzv, IndexOrder moorder = `energy`)

This constructor should be used when the **MOIndexSpace** object is a subspace of a full orbital space. Similarly to the previous constructor, it constructs an **MOIndexSpace** object using a symmetry-blocked transformation coefficient matrix (AO by MO) for the full space, basis set, 'eigenvalues' and the number of orbitals with lowest (nfzc) and highest (nfzv) eigenvalues to be dropped. The orbitals in the constructed space are ordered by energy.

### sc::MOIndexSpace::MOIndexSpace (std::string name, const RefSCMatrix & full\_coefs, const Ref\< GaussianBasisSet \> basis, const Ref\< Integral \> & integral)

This constructor should be used when the **MOIndexSpace** object is the full orbital space. The orbitals will be symmetry-blocked.

### sc::MOIndexSpace::MOIndexSpace (std::string name, const Ref\< MOIndexSpace \> & orig\_space, const RefSCMatrix & new\_coefs, const Ref\< GaussianBasisSet \> & new\_basis)

This constructor is a true hack introduced because I have no idea how to construct what I need. It will copy orig\_space but replace it's coefs with new\_coefs, and its basis with new\_basis.

## Member Function Documentation

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

Prints out this.

Reimplemented from **sc::DescribedClass**.

### void sc::MOIndexSpace::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::SavableState**.

## Author

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