Negative entropy while relaxing metalic system ?!?
Posted: Tue Jul 25, 2006 7:59 am
Hello,
I have a metalic carbon nanotube with Fe inside.
I relax the ions and also the cell shape & volume (using ISIF = 3).
As this is a metalic system, I use ISMEAR = 1 and SIGMA = 0.35,
which gave a small enough entropy with the pure carbon nanotube
(without the Fe atoms).
Now, with the Fe inside, I get negative entropies, like this:
Should I ignore this, or am I doing something completely wrong?
Input files are here:
http://surfion.snu.ac.kr/~lahaye/vasp/
Thanks,
Rob.
I have a metalic carbon nanotube with Fe inside.
I relax the ions and also the cell shape & volume (using ISIF = 3).
As this is a metalic system, I use ISMEAR = 1 and SIGMA = 0.35,
which gave a small enough entropy with the pure carbon nanotube
(without the Fe atoms).
Now, with the Fe inside, I get negative entropies, like this:
Code: Select all
$ grep "entropy T" OUTCAR
entropy T*S EENTRO = -0.03348333
entropy T*S EENTRO = -0.04085538
entropy T*S EENTRO = -0.02225508
entropy T*S EENTRO = 0.01793880
entropy T*S EENTRO = 0.03325612
entropy T*S EENTRO = -0.03050861
entropy T*S EENTRO = 0.02235358
entropy T*S EENTRO = -0.00616872
entropy T*S EENTRO = -0.05104471
entropy T*S EENTRO = 0.00910373
entropy T*S EENTRO = -0.05910159
entropy T*S EENTRO = 0.00575567
entropy T*S EENTRO = -0.07575832
entropy T*S EENTRO = -0.03117156
entropy T*S EENTRO = -0.07769648
...Input files are here:
http://surfion.snu.ac.kr/~lahaye/vasp/
Thanks,
Rob.