  The endeavor to selectively fabricate a cubic diamond is challenging due to
the formation of competing phases such as its hexagonal polymorph or others
possessing similar free energy. The necessity to achieve this is of paramount
importance since the cubic diamond is the only polymorph exhibiting a complete
photonic bandgap, making it a promising candidate in view of photonic
applications. Herein, we demonstrate that due to the presence of an external
field and delicate manipulation of its strength we can attain selectivity in
the formation of a cubic diamond in a one-component system comprised of
designer tetrahedral patchy particles. The driving force of such a phenomenon
is the structure of the first adlayer which is commensurate with the (110) face
of the cubic diamond. Moreover, after a successful nucleation event, once the
external field is turned off, the structure remains stable, paving an avenue
for further post-synthetic treatment.
