---
title: ChunkPart (latest version)
description: API reference for ibm_quantum_schemas.executor.version_1_1.ChunkPart in the latest version of qiskit-ibm-runtime
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit-ibm-runtime/ibm-quantum-schemas-executor-version-1-1-chunk-part
---

# ChunkPart

*pydantic model* `ChunkPart`

[GitHub](https://github.com/Qiskit/ibm-quantum-schemas/tree/0.10.20260723/ibm_quantum_schemas/executor/version_1_1/models.py#L283-L341)

Bases: `BaseModel`

A description of the contents of a single part of an execution chunk.

### element\_range

*field*

Type: `tuple`\[`int`, `int`, `int`]

Which elements of the item were executed in this chunk part.

This range has entries `(start_idx, stop_idx, step)` that slice the flattened shape of the corresponding quantum program item, after the `permutation` has been applied. That is, this part corresponds to the data elements `flatten(permute(arr))[start_idx:stop_idx:step]` for some data array `arr` whose shape matches the corresponding item shape. The lower index is inclusive, the upper index is exclusive, and the step must be positive.

It should hold that `size == max(0, ceil((stop_idx - start_idx) / step))`.

**Validated by**

- `cross_validate`
- `must_be_a_valid_range`

### idx\_item

*field*

Type: `int`

The index of an item in a quantum program.

**Validated by**

- `cross_validate`

### permutation

*field*

Type: `list`\[`int`]

A permutation vector of the item shape before slicing elements with the `element_range`.

This list should hold contiguous integers starting at 0, in some order. The convention is that `permuted_shape[i] = shape[permutation[i]]` for every dimension index `i`.

**Validated by**

- `cross_validate`
- `must_be_permutation_of_range`

### size

*field*

Type: `int`

The number of elements from the quantum program item that were executed.

For example, if a quantum program item has shape `(10, 5)`, then it has a total of `50` elements, so that if this `size` is `10`, it constitutes 20% of the total work for the item.

**Validated by**

- `cross_validate`

### cross\_validate

*validator* `cross_validate`

[GitHub](https://github.com/Qiskit/ibm-quantum-schemas/tree/0.10.20260723/ibm_quantum_schemas/executor/version_1_1/models.py#L332-L341)

Check for mutual compatibility of types and shapes of attributes.

**Return type**

*Self*

### must\_be\_a\_valid\_range

*validator* `must_be_a_valid_range`

[GitHub](https://github.com/Qiskit/ibm-quantum-schemas/tree/0.10.20260723/ibm_quantum_schemas/executor/version_1_1/models.py#L323-L330)

Check that we have a valid range tuple.

### must\_be\_permutation\_of\_range

*validator* `must_be_permutation_of_range`

[GitHub](https://github.com/Qiskit/ibm-quantum-schemas/tree/0.10.20260723/ibm_quantum_schemas/executor/version_1_1/models.py#L315-L321)

Check that we have a valid permutation vector.