[交流] 在线答疑:Wien2k的问题

I have a question about the structure optimization using WIEN2k. I want
to optimize a crystal structure, say, tetragonal ZrO2,
which has three structural variables, the two lattice constants a, c,  
and an internal variable d_z.  WIEN2k provides the functions of
(1) optimize volume with fixed c/a ratio
(2) Optimize c/a ratio with fixed volume
(3) optimize internal variables with fixed lattice constant,
I guess taking different order of these optimization procedures would
lead to different results. Ideally I guess one should repeat these three
procedures
for several times until convergence is reached.
My questions are : are  there any empirical schemes to obtain the
optimized structure more efficiently ? Is the self-consistency really
necessary?
If not,  which order should one take to obtain the most reliable results?

Thank you very much in advance!

In the latest option there is a possibility to generate struct files for
c and a variation simultaneously.

edit optimize.job (and uncomment/adapt the "min_lapw line", comment the
"run_lapw" line.)

This way you simultaneously optimize the internal parameters for each
pair of a and c.

PS: I do this in 2 steps, first with a rather small RKmax+ k-mesh; then
(using the "preoptimized" structures with a better RKmax and k-mesh).
But this requires some experience and "feeling" for proper parameters.

Originally posted by fansw1129 at 2008-12-2 20:42:
估计是编译器没有装好