[Wien] Volume optimization of Sulphur

[shamik chakrabarti]

Dear Wien2k users,

                        I have started volume optimization of S using a cif
file attached herewith using nlvdw. The simulation goes well and presented
a minima in the volume vs energy curve. However, when I opt for the
calculation of unit cell volume for R_3 (space group no. 148) crystal
system with the formula V = a^2 c sin60, the lattice parameter comes out to
be too much smaller (a=b= 7.6 A in comparison to experimental a=b=10.818 A).

Am I doing something wrong in simulating the volume of the rhombohedral
crystal system? (The volume-optimization curve is also attached herewith
this mail)

Any response in this regard will be helpful for us.

with regards,

-- 
Dr. Shamik Chakrabarti
Research Fellow
Department of Physics
Indian Institute of Technology Patna
Bihta-801103
Patna
Bihar, India
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20200310/5ea1212a/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: cif_2_proper_used.cif
Type: application/octet-stream
Size: 1378 bytes
Desc: not available
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20200310/5ea1212a/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 438951-2170.ps
Type: application/postscript
Size: 26371 bytes
Desc: not available
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20200310/5ea1212a/attachment.ps>