[Pw_forum] Run using a relaxed structure as initial one NOT converge in fir st few ionic steps.

[quantum]

Dear QE Friends:

I did a "relax" calculation with PW (version 5.3.0)
and obtained the relaxed atomic positions.

Then, I took the atomic positions
in the last "ATOMIC_POSITIONS (crystal)"
section of the output file to replace the
atomic positions in the original input file
without changing any other things except new
prefix and outdir.

The atoms in the relaxed structure should
all satisfy etot_conv_thr and forc_conv_thr
thresholds.  With this in mind, I started
the new run.

I expected the run to
converge after the first or two ionic steps.
But it did not stop, and continued running
for many ionic steps without convergence.

Is my expectation correct? or it is a problem
of QE?

Sincerely,
Tsung-Lung Li


Tsung-Lung Li, Ph. D.
Professor
Department of Applied Physics
National Chia-Yi University
300 Hsueh-Fu Road, Chiayi 60004, Taiwan
Phone: 886-5-2717904.  FAX: 886-5-2717909.
E-mail:quantum at mail.ncyu.edu.tw    
URL:http://web.ncyu.edu.tw/~quantum