[Pw_forum] Converged SCF total energies different in 6.0/6.1/6.2

[WF]

Dear all,

In tests a normal DFT calculations with Si, I noticed that QE 6.0 and 6.1
gives exactly same total energy with 6.0 and 6.1 (-15.75190880 Ry), but with
QE 6.2.1, the total energy is -15.75191309Ry. I tested this on two different
machines with different compilers, the results are the same across all of
them (at least to last digit). I did some tests on larger systems also and
found even larger difference. This 1e-5 Ry order of difference is not
negligible. Is there anything introduced in 6.2 leads to this difference?
Thanks very much.

 

Best regards,

Feng

 

The input file is attached:

====================

&control

    calculation='scf'

    outdir='./tmp'

    prefix='si'

    wf_collect = .true.,

/

&system

    ibrav=2,

    celldm(1) = 10.263,

    nat=2,

    ntyp= 1,

    ecutwfc = 40,

/

&electrons

    mixing_mode='plain'

    mixing_beta = 0.7,

    conv_thr =  1.0d-10,

/

ATOMIC_SPECIES

Si  1.0 Si_ONCV_PBE-1.1.upf

ATOMIC_POSITIONS {alat}

Si 0.00 0.00 0.00

Si 0.25 0.25 0.25

K_POINTS (automatic)

4 4 4 0 0 0

==============

 

 

--------------------------------------------------

Dr. Feng Wu

Postdoctoral researcher

Department of Chemistry and Biochemistry

University of California, Santa Cruz

Phone: 831-459-2874

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20171220/058148df/attachment.html>