2(acid)/calcite AFF as in Kim &amp; O'Neil (1997), i.e., 10.44 at 25 °C.</p>
<p><code>"KO97"</code>: Kim and O'Neil (1997), reprocessed here to match the IUPAC-recommended
AFF as in Kim et al. (2007, 2015):</p>
<p>$$\alpha^{18}_{calcite/water} =
e^{(18.04 \times \frac{1}{T} - 0.03218)}$$</p>
<p><code>"Coplen07"</code>: Coplen (2007):</p>
<p>$$\alpha^{18}_{calcite/water} =
e^{(17.4 \times \frac{1}{T} - 0.0286)}$$</p>
<p><code>"Tremaine11"</code>: Tremaine et al. (2011):</p>
<p>$$\alpha^{18}_{calcite/water} 