Re: CCL:Partial Optimization



 Hi,
 Maby the ONIOM model by Keiji Morokuma would be worth a look.
 :-)
 /Harald
 On Tue, 9 Jun 1998, Yubo Fan wrote:
 >
 >
 > Hi, everyone:
 >
 > I am doing the geometry optimization of some rather big molecules. Can I
 > split these molecules into some small pieces and optimize them
 > seperately? For example, methyl(4-nitrophenyl)octadecylamine
 > (C18H37N(CH3)C4H4NO2, MNPOA), I want to optimize the geometry of
 > ethylmethyl(4-nitrophenyl)amine (EMNPA) by B3LYP/6-31G*, then change
 > ethyl into octadecyl. Are there some methods in G94W to fix all bond
 > lengths, bond angles and dihedral angles in EMNPA but the ethyl, and
 > change the ethyl into octadecyl? Then do the geometry optimization of
 > NMPOA by PM3 or other semi-empirical methods.
 >
 > With best regards
 >
 > Yubo Fan
 >
 >
 > --
 > =============================================================
 > Yubo Fan                         Email: yubofan %-% at %-% guomai.sh.cn
 > Organic Synthesis Lab                   yubofan %-% at %-% fudan.edu.cn
 > The Department of Chemistry
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 Harald Svedung (M.Sc.)			phone:		+46-31-7722816
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