I. Experimental (solid/red) and deconvolved (dashed/black) FTIR
spectrum of AB-CAp2 in the 890–860 cm−1 carbonate
ν2 region. The 3 fitted curves are also reported,
together with position and assignment (inset table). II. FTIR
spectra of the carbonate ν2 region showing the trend in the
relative A-type and B-type carbonate in a) A-CAp, b) AB-CAp1, c) AB-CAp2, d)
AB-CAp3, e) AB-CAp4.