Dear Rolly,
You could try using other pseudo potentials: The HGH ones indeed require
ecutwfc > 100 Ry, in particular the oxygen.
I guess that the input_dft = 'LDA' was only for a test, right?
Greetings,
apsi
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
Ari Paavo Seitsonen / [email protected] / http://www.iki.fi/~apsi/
Ecole Normale Supérieure (ENS), Département de Chimie, Paris
Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935
On Mon, 7 Dec 2015, Rolly Ng wrote:
Dear QE developers and users,
I am trying to run a “relax” structural optimization of the Biotin molecule
on QE-5.2.0, the default nstep=50 does complete but I made a few
observations on the output file.
(1) “Check: negative starting charge= -0.823869” Is this quite large since
I have only 90 electrons? Is it expected to be 0.001*90=0.009 or less
according to the FAQ.
http://www.quantum-espresso.org/faq/self-consistency/#6.12
(2) It ends by the maximum number of steps reached. Is this normal to end
BFGS geometry optimization?
“energy old = -277.9634535886 Ry
energy new = -277.9645708192 Ry
CASE: energy _new < energy _old
new trust radius = 0.1278123491 bohr
The maximum number of steps has been reached.
End of BFGS Geometry Optimization”
(3) I have increased the nstep=100 and 1000, It only takes long to end the
job but still ended by maximum number of steps reached. Which is very
strange.
(4) I have tried to increase ecutwfc=200.0d0, ecutrho=800.0d0, then the
negative starting charge becomes much smaller to -0.000171
(5) How can I speed up this task?
Please take a look at the input file as attached. Any comment are welcome.
Thanks,
Rolly
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