The static dipole polarizability and the hardness of some new carbon hypermagnesium species

Very recently, Boldyrev and Simons (J. Phys. Chem., A101 1997 902) presente d a theoretical study of the new molecule Mg2C which has not been experimen tally detected, yet. They found that it is a very difficult case for theore tical methods, because there are four states lying in an energy range of 4 kcal/mol. Therefore, at the actual level of numerical accuracy of the theor etical calculations it is impossible to conclude which is the ground state. In this article it is shown that the hardness and the dipole polarizabilit y yield valuable information about the four states in question. In particul ar, the dipole polarizability could help in detecting the molecule and deci ding which state is the most populated. (C) 1999 Elsevier Science B.V. All rights reserved.