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<DIV><FONT size=2>hello all!</FONT></DIV>
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<DIV><FONT size=2>I want to stretch a DNA molecule, but which method shoud I use
?</FONT></DIV>
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<DIV><FONT size=2>the afm? constraint? or constant
acceleration?</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>but every method has some problems.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>i.e. add the acceleration on some atoms. I have to (1)freeze
some atoms at the other end (2)and set the parameter comm-mode=
linear. When stretching, they conflict with each other. the result is
completely wrong. Use afm is in the same situation.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>constraint may be better.but the result can not compared with
other paper.</FONT></DIV>
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<DIV><FONT size=2>Thank you very much for kindly
replys</FONT></DIV></FONT></DIV></FONT></DIV></BODY></HTML>