Hi Yusia,
my experience with siesta is small so maybe I am wrong, but
for the Energyshift it is better to have a smaller value so the cut-off radius
of the orbitals is longer and thus, the basis set is more extended. Also, a
smaller PAO.EnergyShift reduces the BSSE very much. I think that the deafult
value 0.02 Ry is not the best choice, at least 0.01 Ry is needed.
Best,
pablo
----- Original Message -----
From: Yusia Rosee
To: SIESTA-L@listserv.uam.es
Sent: Tuesday, November 04, 2008 12:28 PM
Subject: Re: [SIESTA-L]
I have one question. From your figure, you only did the calculation for
energy shift up to 50meV. But in a real calculation, we often set it as
200~300meV. So do you think 50meV is enough?
Yusia
On Tue, Nov 4, 2008 at 2:13 AM, Xu Lu <[EMAIL PROTECTED]> wrote:
Dear Eduardo and all:
Thank you very much for your reply. Here I give you one of
my input files and other information:
===================== start of input file=========================
SystemName carbon atom # Descriptive name of the system
SystemLabel C-atom # Short name for naming files
# Species and atoms
NumberOfSpecies 1
NumberOfAtoms 1
%block ChemicalSpeciesLabel
1 6 C
%endblock ChemicalSpeciesLabel
# Basis (TZP)
%block PAO.Basis # Define Basis set
C 2 # Species label, number of l-shells
n=2 0 3 # n, l, Nzeta
0.000 0.000 0.000
1.000 1.000 1.000
n=2 1 3 P 1 # n, l, Nzeta, Polarization, NzetaPol
0.000 0.000 0.000
1.000 1.000 1.000
%endblock PAO.Basis
PAO.EnergyShift 10 meV
xc.functional LDA # Default value
xc.authors PZ # Default value
MeshCutoff 300. Ry
OccupationFunction MP
ElectronicTemperature 100 K
# SCF options
MaxSCFIterations 150 # Maximum number of SCF iter
DM.NumberPulay 5
DM.MixingWeight 0.20 # New DM amount for next SCF cycle
DM.Tolerance 1.d-4 # Tolerance in maximum difference
# between input and output DM
# Atomic coordinates
AtomicCoordinatesFormat Ang
%block AtomicCoordinatesAndAtomicSpecies
0.000000000000 0.000000000000 0.000000000000 1
%endblock AtomicCoordinatesAndAtomicSpecies
======================= end of input file=========================
You can also have a look at a plot of my total energy convergence
results with respect to energy shift.
https://www.msu.edu/~luxu/singlecarbon-data.png
It seems hard to achieve Self-Consistency at zero electronic
temperature, I used electron temperature at 100.0 K and MP
(Methfessel-Paxton)occupation function and I hope this set up
is not the reason of problems.
Thank you again for your kind helps!
Sincerely yours,
Xu Lu
======================================
Xu Lu
---------------
Physics and Astronomy Department
4240 Biomedical &Physical Sci. Bldg
Michigan State University
East Lansing, MI 48824-2320 USA
(517)884-5672 (office)
(517)4205973 (mobile)
(517)353-4500 (FAX)
http://www.msu.edu/~luxu
======================================
Eduardo Anglada writes:
Hi,
Could you please post your results and the input fdf?
The energy should converge.
Best
Eduardo
On 01/11/2008, at 15:23, Xu Lu wrote:
Dear all :
I have a problem in calculating the energy of single atom. The
energy will drop linearly with respect to decreasing of energy shift.
It
seems that the energy does not converge with respect to energy shift.
What is the problem with single atom calculation ? Do I need to
consider the energy shift convergence in this calculation.
