Cover Image, Volume 113, Issue 5


original image

The cover image is a stylized drawing of the MgB2 cell containing an impurity cation incorporated into the magnesium sublattice. In the work by Aleksandr Pishtshev and Mihhail Klopov on page 643, it is found that the substitution not only always affects the existing overall picture of the electronic states involved in the chemical bonding, but also that the resulting charge rearrangement around the host cation position is exhibited quite differently among substitutional ions considered. In the context of superconductivity, these features can seriously limit the targeting efficiency of a number of potential substituents or even make them unfavorable toward the enhancement of superconducting properties.