Hi, When you increase the energy shift then you decrease the cutoff radii, so the energy increases. The behaviour of your plot is exactly what you should expect. What you should converge is the total energy of your condensed system, formed by multiple atoms. In that situation the energy should converge (with a tolerance of a few mev) with respect to the energy shift. Best regards, Eduardo
On 03/11/2008, at 19:13, Xu Lu 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. Theenergy 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.
