  Due to its potential for implementing a scalable quantum computer, multiqubit
Toffoli gate lies in the heart of quantum information processing. In this
article, we demonstrate a multiqubit blockade gate with atoms arranged in a
three-dimension spheroidal array. The gate performance is greatly improved by
the method of optimizing control-qubit distributions on the spherical surface
via evolutionary algorithm, which leads to an enhanced asymmetric Rydberg
blockade. This spheroidal configuration, not only arises a well preservation
for the dipole blockade energy between arbitrary control-target pairs, which
keeps the asymmetric blockade error at a very low level; but also manifests an
unprecedented robustness to the spatial position variations, leading to a
negligible position error. Taking account of intrinsic errors and with typical
experimental parameters, we numerically show that a C$_6$NOT Rydberg gate can
be created with a fidelity of 0.992 which is only limited by the Rydberg state
decays.Our protocol opens up a new platform of higher-dimensional atomic arrays
for achieving multiqubit neutral-atom quantum computation.
