  Symmetry plays a fundamental role in condensed matter. The unique
entanglement between magnetic sublattices and alternating crystal environment
in altermagnets provides a unique opportunity for designing magnetic space
symmetry. There have been extensive experimental efforts concentrated on tuning
the Neel vector to reconstruct altermagnetic symmetry. However, it remains
challenging to modulate the altermagnetic symmetry through the crystal aspect.
Here, the crystal design of altermagnetism is successfully realized, by
breaking glide mirrors and magnetic mirrors of the (0001) crystallographic
plane in CrSb films via crystal distortion. We establish a locking relationship
between altermagnetic symmetry and the emergent Dzyaloshinskii-Moriya (DM)
vectors in different CrSb films, realizing unprecedentedly room-temperature
spontaneous anomalous Hall effect in an altermagnetic metal. The concept of
exchange-coupling torques is broadened to include both antiferromagnetic
exchange-coupling torque and DM torque. Their relationship is designable,
determining electrical manipulation modes, e.g., field-assisted switching for
CrSb(1-100)/Pt and field-free switching for W/CrSb(11-20). Particularly, the
unprecedentedly field-free 100-percent switching of Neel vectors is realized by
making these two torques parallel or antiparallel, dependent on Neel vector
orientation. Besides unravelling the rich mechanisms for electrical
manipulation of altermagnetism rooted in broadened concept of exchange-coupling
torques, we list other material candidates and propose that crystal design of
altermagnetism would bring rich designability to magnonics, topology, etc.
