Subject: Partial Optimization

From: Yubo Fan <[email-masked]>
Date: Tue, 09 Jun 1998 23:41:35 +0800

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

--
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Yubo Fan                         Email: [email-masked]
Organic Synthesis Lab                   [email-masked]
The Department of Chemistry
Fudan University                 Phone: 8621-65648139
No. 220 Handan Road              Fax:   8621-65641740
Shanghai, 200433
P. R. China
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