3 of 10 MathJaxed chemistry

# How many $Ga$ atoms are connected to one $As$ atom in solid state Gallium arsenide

Let's start straight away. In this book on page 4 Gallium arsenide's bond structure is shown like this:

$$As$$ is shown making $$5$$ covalent bonds.
Recently I came across this book. The bond structure of $$\ce{GaAs}$$ is shown like this:
.

Here $$\ce{As}$$ is shown to make $$4$$ covalent bonds. For sure one of the above quoted images is wrong. But which?

To how many $$\ce{Ga}$$ atoms one $$\ce{As}$$ atom is connected? Actually. Please explain your answer with established reference(s) and also give experimental proof in your answer that supports your answer.