Hello,<br>
<br>
I wanted to know your ideas on calculation of heat of vaporization using
a single phase run rather than running two separate simulations for
liquid and gas!<br>
<br>
1- Two separate simulations for liquid and gas<br>
<br>
DHvap = <Ugas> - <Uliq> + RT<br>
<br>
1a: <total liquid potential> - <<b>total</b> potential of
a single chain in vacu > ( bond+angle+torsion + nonbonded interaction of chain with itself)<br>
<br>
or<br>
<br>
1b: <i><total liquid potential> - < <b>intra</b> potential of
a single chain in vacu > ( bond+angle+torsion) </i><br>
<br>
2- Single liquid phase run: (non need to run in vacu) <br>
<br>
2a : DHvap = <total liquid potential> - < intra molecular
potential terms in liquid phase> (same
liquid phase simulation by adding up bond+angle+torsion terms)<br>
<br>
2a: In other worlds <i>DHvap= <Uliq-nonbonded (vdw+electrostatics)> </i><br>
<br>
In my case the latter definition is giving much more accurate results than 1a. <br>
<br>
I
would like to know your idea and comments on methods 1b and 2a.<br>
<br>
Appreciate your comments.<br>
<br>
Best,