1. B. A. Frenz,Enraf-Nonius SDP-Plus Structure Determination Package, Version 3.0, Delft (1985).
2. P. T. Beurskens, G. Admiraal, G. Beurskens, et al.,The DIRDIF-94 Program System, University of Nijmegen, The Netherlands (1994).
3. G. M. Sheldrick,Acta Crystallogr.,A49 (Suppl.), S53 (1993).
4. J. J. P. Stewart,MOPAC6.0, QCPE Program No. 455 (1990).
5. F. H. Allen and O. Kennard,Chem. Des. Automat. News,8, 31–37 (1993).