(IUCr) Phosphonoacetic acid

Figure 10
Part of the crystal structure of (4), which shows the formation of a chain of anions along [01 $[\bar 1]$ ]. This chain contains spiro-fused R₂²(8) and R₂²(12) rings. For the sake of clarity, H atoms bonded to C atoms are omitted. The atoms marked with an asterisk (*), hash (#) or dollar sign ($) are at the symmetry positions (-x, 2 - y, -z), (-x, 1 - y, 1 - z) and (x, -1 + y, 1 + z), respectively.