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mismatched energy values on same symmetry points Date: 2014/12/02 18:30 Name: Kuraya Dear prof. Ozaki, The narrow-gap semiconductor PbTe's energy band was calculated on same symmetry L points by OpenMX 3.7. PbTe is the rock-salt structure. But, those top of the valence band energy values did not match. The energy value on [0.5 0.5 0.5] is 0.02eV higher than on another symmetry points. Do you have any idea how to solve this problem? In OpenMX method, should we not require more precision? Kuraya //////////////////////////////////////////////////////////////////////////////////// .dat file Species.Number 2 <Definition.of.Atomic.Species Pb Pb12.0-s1p1d1f1 Pb_PBE13 Te Te11.0-s1p1d1f1 Te_PBE13 Definition.of.Atomic.Species> Atoms.Number 2 scf.XcType GGA-PBE # LDA―LSDA-CA―LSDA-PW―GGA-PBE scf.SpinPolarization nc # On―Off―NC scf.SpinOrbit.Coupling on # On―Off, default=off scf.Kgrid 12 12 12 # means n1 x n2 x n3 Band.Nkpath 2 <Band.kpath 50 0.5 0.5 0.5 0.0 0.0 0.5 L L 50 0.0 0.0 0.5 0.0 0.5 0.0 L L Band.kpath> ////////////////////////////////////////////////////////////////////////////////////

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Re: mismatched energy values on same symmetry points ( No.1 ) Date: 2014/12/05 00:50 Name: Artem Pulkin  <artem.pulkin@epfl.ch> To restore the symmetry, you may go for a larger cutoff. Re: mismatched energy values on same symmetry points ( No.2 ) Date: 2014/12/10 12:04 Name: Kuraya Dear Artem , Thank you for your kind reply. I changed these parameters. //////////////////////////////////////////////////////////////////////////////////// .dat file Species.Number 2 <Definition.of.Atomic.Species Pb Pb12.0-s1p1d1 Pb_PBE13 Te Te11.0-s1p1d1 Te_PBE13 Definition.of.Atomic.Species> scf.energycutoff 250.0 # default=150 (Ry) scf.ProExpn.VNA off # on|off, default = on //////////////////////////////////////////////////////////////////////////////////// The difference of the values became 0.00085941 eV. Really thanks for your help, Best Regards, Kuraya Re: mismatched energy values on same symmetry points ( No.3 ) Date: 2014/12/11 22:12 Name: T. Ozaki Hi, I noticed that the basis set you used may not be enough to get accurate results. A proper choice for basis functions can be Pb Pb8.0-s2p2d2f1 Pb_PBE13 Te Te7.0-s2p2d2f1 Te_PBE13 to obtain a reasonably convergent result. Regards, TO

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