qiskit-documentation/docs/api/qiskit/0.30/qiskit.circuit.library.MCMTVChain.mdx

---
title: MCMTVChain
description: API reference for qiskit.circuit.library.MCMTVChain
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.circuit.library.MCMTVChain
---

# MCMTVChain

<Class id="qiskit.circuit.library.MCMTVChain" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.18/qiskit/circuit/library/generalized_gates/mcmt.py" signature="MCMTVChain(gate, num_ctrl_qubits, num_target_qubits, label=None)" modifiers="class">
  Bases: `qiskit.circuit.library.generalized_gates.mcmt.MCMT`

  The MCMT implementation using the CCX V-chain.

  This implementation requires ancillas but is decomposed into a much shallower circuit than the default implementation in [`MCMT`](qiskit.circuit.library.MCMT "qiskit.circuit.library.MCMT").

  **Expanded Circuit:**

  **Examples:**

  > ```python
  > >>> from qiskit.circuit.library import HGate
  > >>> MCMTVChain(HGate(), 3, 2).draw()
  > ```
  >
  > **q\_0: ──■────────────────────────■──**
  >
  > │ │
  >
  > **q\_1: ──■────────────────────────■──**
  >
  > │ │
  >
  > **q\_2: ──┼────■──────────────■────┼──**
  >
  > │ │ ┌───┐ │ │
  >
  > **q\_3: ──┼────┼──┤ H ├───────┼────┼──**
  >
  > │ │ └─┬─┘┌───┐ │ │
  >
  > **q\_4: ──┼────┼────┼──┤ H ├──┼────┼──**
  >
  > ┌─┴─┐ │ │ └─┬─┘ │ ┌─┴─┐
  >
  > **q\_5: ┤ X ├──■────┼────┼────■──┤ X ├**
  >
  > └───┘┌─┴─┐ │ │ ┌─┴─┐└───┘
  >
  > **q\_6: ─────┤ X ├──■────■──┤ X ├─────**
  >
  > └───┘ └───┘

  Create a new multi-control multi-target gate.

  **Parameters**

  *   **gate** (`Union`\[`Gate`, `Callable`\[\[`QuantumCircuit`, `Qubit`, `Qubit`], `Instruction`]]) – The gate to be applied controlled on the control qubits and applied to the target qubits. Can be either a Gate or a circuit method. If it is a callable, it will be casted to a Gate.
  *   **num\_ctrl\_qubits** (`int`) – The number of control qubits.
  *   **num\_target\_qubits** (`int`) – The number of target qubits.
  *   **label** (`Optional`\[`str`]) – The name for the controlled circuit block. If None, set to C-name where name is gate.name.

  **Raises**

  *   **AttributeError** – If the gate cannot be casted to a controlled gate.
  *   **AttributeError** – If the number of controls or targets is 0.

  ## Methods Defined Here

  ### inverse

  <Function id="qiskit.circuit.library.MCMTVChain.inverse" signature="MCMTVChain.inverse()">
    Return the inverse MCMT circuit, which is itself.
  </Function>

  ## Attributes

  ### ancillas

  <Attribute id="qiskit.circuit.library.MCMTVChain.ancillas">
    Returns a list of ancilla bits in the order that the registers were added.
  </Attribute>

  ### calibrations

  <Attribute id="qiskit.circuit.library.MCMTVChain.calibrations">
    Return calibration dictionary.

    **The custom pulse definition of a given gate is of the form**

    \{‘gate\_name’: \{(qubits, params): schedule}}
  </Attribute>

  ### clbits

  <Attribute id="qiskit.circuit.library.MCMTVChain.clbits">
    Returns a list of classical bits in the order that the registers were added.
  </Attribute>

  ### data

  <Attribute id="qiskit.circuit.library.MCMTVChain.data">
    Return the circuit data (instructions and context).

    **Returns**

    a list-like object containing the tuples for the circuit’s data.

    Each tuple is in the format `(instruction, qargs, cargs)`, where instruction is an Instruction (or subclass) object, qargs is a list of Qubit objects, and cargs is a list of Clbit objects.

    **Return type**

    QuantumCircuitData
  </Attribute>

  ### extension\_lib

  <Attribute id="qiskit.circuit.library.MCMTVChain.extension_lib" attributeValue="'include &#x22;qelib1.inc&#x22;;'" />

  ### global\_phase

  <Attribute id="qiskit.circuit.library.MCMTVChain.global_phase">
    Return the global phase of the circuit in radians.
  </Attribute>

  ### header

  <Attribute id="qiskit.circuit.library.MCMTVChain.header" attributeValue="'OPENQASM 2.0;'" />

  ### instances

  <Attribute id="qiskit.circuit.library.MCMTVChain.instances" attributeValue="16" />

  ### metadata

  <Attribute id="qiskit.circuit.library.MCMTVChain.metadata">
    The user provided metadata associated with the circuit

    The metadata for the circuit is a user provided `dict` of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.
  </Attribute>

  ### num\_ancilla\_qubits

  <Attribute id="qiskit.circuit.library.MCMTVChain.num_ancilla_qubits">
    Return the number of ancilla qubits required.
  </Attribute>

  ### num\_ancillas

  <Attribute id="qiskit.circuit.library.MCMTVChain.num_ancillas">
    Return the number of ancilla qubits.
  </Attribute>

  ### num\_clbits

  <Attribute id="qiskit.circuit.library.MCMTVChain.num_clbits">
    Return number of classical bits.
  </Attribute>

  ### num\_parameters

  <Attribute id="qiskit.circuit.library.MCMTVChain.num_parameters">
    Convenience function to get the number of parameter objects in the circuit.
  </Attribute>

  ### num\_qubits

  <Attribute id="qiskit.circuit.library.MCMTVChain.num_qubits">
    Return number of qubits.
  </Attribute>

  ### parameters

  <Attribute id="qiskit.circuit.library.MCMTVChain.parameters">
    Convenience function to get the parameters defined in the parameter table.
  </Attribute>

  ### prefix

  <Attribute id="qiskit.circuit.library.MCMTVChain.prefix" attributeValue="'circuit'" />

  ### qubits

  <Attribute id="qiskit.circuit.library.MCMTVChain.qubits">
    Returns a list of quantum bits in the order that the registers were added.
  </Attribute>
</Class>