Lead
S.J.A van Gisbergen, J.G. Snijders, and E.J. Baerends, J. Chem. Phys. 109, 10644 (1998)
Suggested:
S.J.A van Gisbergen, J.G. Snijders, and E.J. Baerends, Phys. Rev. Lett. 78, 3097 (1997)
