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ecutsm parameter

From: "Nichols A. Romero" <naromero@gmail.com>
To: forum@abinit.org
Subject: ecutsm parameter
Date: Tue, 4 Oct 2005 16:50:50 -0400
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Hi,

I have been doing some benchmark comparisons between PWSCF and ABINIT with identical pseudopotentials generated by OPIUM on a simple test case: diamond.

I was doing simple SCF, with identical kpts, ecut, lattice constant, etc.

The two did not agree with one another until I set ecutsm = 0.0. I had accidentally left is set to 0.5 Ha from a previous relaxation calculation.

Now, I understand that ecutsm is primarily used for variable cell relaxation. But on these simple scf calculations, it caused the pressure to differ by 30 GPa (quite a bit).

I would not have expected such a difference. Is this normal? I am using relatively hard norm-conserving PP (r_c=1.1) of the Troullier-Martins type with Ecut = 50 Ry.

I would appreciate any comments.

Thanks,
--
Nichols A. Romero, PhD.
1613 Denise Dr. Apt. D
Forest Hill, MD 21050
(217) 417-5210

ecutsm parameter, Nichols A. Romero, 10/04/2005
- Message not available
  - Re: ecutsm parameter, Eric J. Walter, 10/05/2005