Question about free energy of conformation change

From: Peiquan Chen (namd_at_eyou.com)
Date: Thu Nov 09 2006 - 02:26:46 CST

Hi all,

I am going to use the free energy of conformational changes module in NAMD to study the free energy profile roting of one bond of my inhibitor. But just as I am a newbie in this class of calculation, I have something uncertain and want to know.

In my configuration file, I have define as following.

freeEnergy on
freeEnergyConfig {

   urestraint {
   dihe pmf (MAIN,1,C16) (MAIN,1,N18) (MAIN,1,C20) (MAIN,1,N21) barr=20, low=-180.0, high=180.0
}

mcti {
  task = stepup
  equiltime = 50 ps
  accumtime = 250 ps
  numsteps = 36
  print = 1 ps
}
}

I have the following question:

1. I don't know which value for barr is suitable for my molecule. I just take 20 as described in the use guide.

2. Which values I should take in equiltime and accumtime?

3. How to judge I have done a succesful simulation if we don't have any experimental data about the conformation change.

Any commment will be appreciated!

Sincerely yours

----
PeiQuan Chen
_______________________________________________________________________________
PeiQuan Chen, Ph.D Student, Department of Chemistry, Nankai University
WeiJin Road 94, TianJin, 300071, P.R.China
phone:	(86)2223494034(HOME) (86)23504991(LAB) Mobile Phone: (+86)13920675030
pqchen_at_mail.nankai.edu.cn
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

This archive was generated by hypermail 2.1.6 : Wed Feb 29 2012 - 15:44:09 CST