def METHOD_NAME(nqubits, dense=True, backend=None):
    """Non-interacting Pauli-X Hamiltonian.
    .. math::
        H = - \\sum _{i=0}^N X_i.
    Args:
        nqubits (int): number of quantum bits.
        dense (bool): If ``True`` it creates the Hamiltonian as a
            :class:`qibo.core.hamiltonians.Hamiltonian`, otherwise it creates
            a :class:`qibo.core.hamiltonians.SymbolicHamiltonian`.
    """
    return _OneBodyPauli(nqubits, matrices.METHOD_NAME, dense, backend=backend)