CCL: structure optimization in CoMFA?



Dear all,
 I attempt to use the molecular structure optimized using ab inito
 method in CoMFA analysis. However, I find the result is much poor than
 that using structure optimized using molecular mechanics (powell
 method). I don't know why.
 Any suggestions will be appreciated. Thank you for your consideration
 on this matter.
 Best wishes,
 Jinsong
 =====
 (Mr.) Jinsong Zhao
 Ph.D. Candidate
 School of the Environment
 Nanjing University
 No.22 Hankou Road, Najing 210093
 P.R. China
 E-mail: zh_jinsong.-at-.yahoo.com.cn
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