Clearly, different anchor species will lead to different values of the chemical potentials for the elements, which in turn affects the relative enthalpies as shown in Fig. . However, as demonstrated by Eq. ( ), the reaction enthalpies of any stoichiometrically balanced reaction will be conserved in an atomic reference basis set. Instead of manually selecting the anchor species to determine the chemical potentials of the elements in a sequential approach, it is possible to exploit the invariance and select convenient numerical values for the chemical potentials. In particular, it is often convenient to select chemical potentials that minimize the (sum of squared) errors between relative enthalpies computed using different codes, levels of fidelity, or reference sets. As we will show, this can be achieved using linear algebra and least-squares regression and avoids the need to specify any explicit chemical species as anchors.