Dear Sir,
Following your instrctions and what I understand from the manual,
for variable cell relaxation, I use
MD.VariableCell .true.
and MD.MaxStressTol 0.5 GPa
Then in the hexagonal geometry both in-plane lattice constant(a)
and perpendicular to the plane(c) are changing.
But I want "a" to remain constant and ONLY c and atomic positions
to relax. So what should I use?
The part of my input file:
=======================================================================
# Eigenvalue problem: order-N or diagonalization
SolutionMethod diagon # OrderN or Diagon
ElectronicTemperature 300 K # Temp. for Fermi smearing
# Molecular dynamics and relaxations
MD.TypeOfRun cg # Type of dynamics:
#MD.TypeOfRun FC # Type of dynamics:
MD.NumCGsteps 50
MD.VariableCell .true. # optimisation of the cell as well
MD.MaxStressTol 0.5 GPa
==========================================================================
Best regards, mousumi.
> Mousumi,
> Try using "MD.VariableCell .true." in addition to the "MD.TypeOfRun
cg" string, together with the target stress and target pressure strings (see
> manual). This will automatically optimize everything.
> Good luck,
> Marcos
> On Sat, 2 Jul 2005 10:14:32 +0530, Mousumi Upadhyay Kahaly wrote
> > Dear All,
> >
> > I am working on a hexagonal system; the in-pnane lattice
constant
> > a=b are kept fixed. But I need to vary c i.e. lattice constant
perpendicular to the plane(so that optimised c/a value is
> > obtained) as well as the atomic positions.
> >
> > Atomic positions vary when I use "MD.TypeOfRun cg".> >
But how do I get optimisation of c at the same time(without
doing it
> > manually)?
> >
> > Can anyone please tell me the sring or blockname for this
purpose?
> >
> > best regards. mousumi.
> ----
> Dr. Marcos Verissimo Alves
> Departamento de Física
> Universidade Federal de São Carlos
> São Carlos, SP - Brasil
> http://joselitosn.df.ufscar.br/~dm/equipe/verissim.htm
> ***********************************
> Dr. Marcos Verissimo Alves
> Physics Department
> Universidade Federal de Sao Carlos
> Sao Carlos, SP - Brazil
> http://joselitosn.df.ufscar.br/~dm/equipe/verissim-en.htm
