Lead
V.P. Osinga, S.J.A van Gisbergen, J.G. Snijders, and E.J. Baerends, J. Chem. Phys. 106, 5091 (1997)
Suggested
S.J.A van Gisbergen, J.G. Snijders, and E.J. Baerends, J. Chem. Phys. 103, 9347 (1995)
