The diamond structure of the preceding scene requires atoms having four bonding electrons.
But a very similar "zincblende" structure is formed by pairing atoms with an average of four bonding electrons. For instance, atoms with three bonding electrons (column III of the periodic table - shown in gold) can pair with atoms with five bonding electrons (column V of the periodic table - shown in blue) to form "III-V compound semiconductors" such as GaAs.
Even more complex "zincblende" crystals are formed when atoms on the gold sites are mixtures of column III atoms (e.g. In and Ga) and blue atoms are mixtures of column V atoms (e.g. As and P). This produces the InGaAsP crystals used in the lasers of fiber-optic telecommunication links.