Exploring chemical space with alchemical derivatives: alchemical transformations of H through Ar and their ions as a proof of concept

Abstract

Alchemical derivatives have been used previously to obtain information about transformations in which the number of electrons is unchanged. Here an approach for combining changes in both the number of electrons and the nuclear charge is presented.

Evaluating quantum alchemy of atoms with thermodynamic cycles: Beyond ground electronic states

“…Previous work using conceptual DFT in predicting atomic properties had also seen a dependence on transmutation direction. 33 This observed asymmetry in errors was also noted in work by others on diatomic molecules, which showed that the description of different target systems using the basis set of one reference system relied on the direction of ∆Z. 48 In the case for atoms, this appears to be due to the augmented finite basis sets for one element generally being slightly more suitable when describing anions than cations of another element.…”

“…To achieve a fundamental understanding of the general accuracy and transferability of these Taylor series approximations, we report the performance of quantum alchemy using Taylor series expansions in predicting electronic energies of single atoms and compare to experimentally observable quantities such as ionization energies, electron affinities, and spin multiplet gaps. Earlier work in this direction 33 , evaluating the alchemical derivatives in the context of conceptual DFT, focused on DFT methods. In this work, we study a correlated wavefunction method, namely the more accurate but more expensive CCSD(T) approach.…”

Links among the Fukui potential, the alchemical hardness and the local hardness of an atom in a molecule

“…The left side of Equation ( 15) has been previously identified as an alchemical derivative. 39,43,[47][48][49][50][51][52][53][54][55][56][57][58][59] Alchemical derivatives are derivatives of the energy with respect to the atomic number of the atoms of a molecule. [46][47][48][49][50][51][52][53][54][55][56][57][58] Indeed, for a discrete distribution of nuclear charge, Equation ( 15) is the negative of derivative of the chemical potential with respect to the atomic numbers, also known as the alchemical (local) hardness, η alchem k , 53…”

“…The left side of Equation () has been previously identified as an alchemical derivative 39,43,47–59 46–58 .…”

“…The left side of Equation () has been previously identified as an alchemical derivative 39,43,47–59 46–58 . Indeed, for a discrete distribution of nuclear charge, Equation () is the negative of derivative of the chemical potential with respect to the atomic numbers, also known as the alchemical (local) hardness, , 53 Although definitions of the local hardness in Equations () and () involved certain ambiguity, they have proved to be useful in describing the local distribution of hardness of molecules.…”