# sc_R12IntsAcc man page

sc::R12IntsAcc — **R12IntsAcc** accumulates transformed (MO) integrals stored as (ijxy) where i, j, x, and, y lie in spaces I, J, **X**, and **Y**, respectively.

## Synopsis

`#include <r12ia.h>`

Inherits **sc::SavableState**.

Inherited by **sc::R12IntsAcc_MemoryGrp**, **sc::R12IntsAcc_MPIIOFile**, and **sc::R12IntsAcc_Node0File**.

### Public Types

enumtbint_type{eri=0,r12=1,r12t1=2,r12t2=3 }Types of two-body operators thatR12IntsAccunderstands. "

### Public Member Functions

R12IntsAcc(intnum_te_types, intni, intnj, intnx, intny)R12IntsAcc(StateIn&)

voidsave_data_state(StateOut&)Save the base classes (with save_data_state) and the members in the same order that theStateInCTOR initializes them.

intnum_te_types() constThe number of types of integrals that are being handled together.

intni() constRank of index space i.

intnj() constRank of index space j.

intnx() constRank of index space x.

intny() constRank of index space y.

size_tblocksize() constSize of each block of the integrals of one type, in double words.

intnext_orbital() constThe index of the first orbital in the next integrals batch to be stored.

virtual voidstore_memorygrp(Ref<MemoryGrp> &mem, intni, const size_t blksize=0)=0Stores all pair block of integrals held in mem in a layout assumed throughoutMBPT2_R12.

virtual voidstore_pair_block(int i, int j, double *ints)=0All member functions of this class and its children indices i and j don't include frozen orbitals Stores an ij pair block of integrals (assumes the block resides locally)

virtual voidcommit()Commit the content of the accumulator for reading.

boolis_committed()Has the content of the accumulator been commited for reading?

virtual voidactivate()Call before starting to read content.

virtual voiddeactivate()Call when done reading content.

const boolis_active()Check if can read content.

virtual double *retrieve_pair_block(int i, int j,tbint_typeoper_type)=0Retrieves an ij pair block of integrals.

virtual voidrelease_pair_block(int i, int j,tbint_typeoper_type)=0Releases an ij pair block of integrals (if needed)

virtual boolis_local(int i, int j) const =0Is this block stored locally?

virtual boolis_avail(int i, int j) const =0Is this block available to this task?

virtual boolhas_access(int proc) const =0Does this task have access to all the integrals?

inttasks_with_access(vector< int > &twa_map) constReturns the total number of tasks with access to integrals.

virtual boolcan_restart() const =0Can this specialization be used in restarts?

### Static Public Attributes

static const intmax_num_te_types_= 4

### Protected Member Functions

virtual intntasks() const =0total number of tasks

virtual inttaskid() const =0ID of this task.

voidinc_next_orbital(intni)The index of the first orbital in the next integrals batch to be stored.

### Protected Attributes

intni_

intnj_

intnx_

intny_

size_tnxy_

size_tblksize_

size_tblocksize_

intnext_orbital_

boolcommitted_

boolactive_

### Additional Inherited Members

## Detailed Description

**R12IntsAcc** accumulates transformed (MO) integrals stored as (ijxy) where i, j, x, and, y lie in spaces I, J, **X**, and **Y**, respectively.

ijxy is only the storage format, the actual type may be (ix|jy), (ij|xy), etc.

Transformed integrals are usually computed using a parallel MO integrals transformation procedure. In general, such transformations will require multiple passes through AO integrals. Each pass produces a batch of transformed integrals. For example, a batch in direct parallel MP2 energy algorithm is a set of integrals {(ix|jy)} in which i indices are in a finite subrange of O and x, j, and y take any of their allowed values. For example, if batch I contains all integrals (ix|jy) with i greater than or equal m but less than n, then batch I+1 contains integrals (ix|jy) with i greater than n. Integrals in batch 0 have indices i greater than or equal to 0.

After each pass the MO integrals are contained in a **MemoryGrp** object. The object is 'stored' in accumulator using `store_memorygrp(Ref<MemoryGrp>& mem, int ni)`

. After all batches have been stored, the content of **R12IntsAcc** needs to be 'committed' using **commit()**. After that blocks of MO integrals can be accessed using `retrieve_pair_block`

.

## Member Function Documentation

### void sc::R12IntsAcc::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**.

Reimplemented in **sc::R12IntsAcc_MPIIOFile_Ind**, **sc::R12IntsAcc_MPIIOFile**, **sc::R12IntsAcc_Node0File**, and **sc::R12IntsAcc_MemoryGrp**.

### virtual void sc::R12IntsAcc::store_memorygrp (Ref< MemoryGrp > & mem, int ni, const size_t blksize = 0) [pure virtual]

Stores all pair block of integrals held in mem in a layout assumed throughout **MBPT2_R12**. Let's suppose the number of tasks is nproc, nj is the number of j indices, ni is the number of i indices of integrals held in mem at the moment. Then all integrals with a given i and j are stored on task (i*nj+j)/nproc and this ij block is (i*nj+j)nproc -th block on this task. Each ij block contains num_te_types_ subblocks of integrals. Each subblock of integrals has blksize bytes allocated for it. Note that blksize may be larger than blksize_ because an ij-block of partially transformed integrals may be larger than the block of fully transformed integrals.

Implemented in **sc::R12IntsAcc_MPIIOFile_Ind**, **sc::R12IntsAcc_Node0File**, and **sc::R12IntsAcc_MemoryGrp**.

### int sc::R12IntsAcc::tasks_with_access (vector< int > & twa_map) const

Returns the total number of tasks with access to integrals. If task i has access to the integrals, then twa_map[i] is its index among the tasks with access, -1 otherwise.

## Author

Generated automatically by Doxygen for MPQC from the source code.