hi, thank you for the explanations.
i read some book and found that the diamagnetism is a normal, universal
characteristic of the material, it is covered by other magnetism in
non-diamagnetic materials.
and some other told me that: paramagnetism is random orientation of spins
throughout the material,
Diamagnetism is local magnetic moment (no spins).So non spin-magnetisation
calculation is indeed the closest thing to diamagnetism simulation.
Duy Le said Diamagnetic materials are either AFM or FM, but there are
diamagnetic materials, like Cu, Ag.
so, could I comprehend like this:
when do a calculation for AFM and FM materials, just do as Duy Le, Hui Wang
and Paolo Giannozzi said.
when do a calculation for DM materials or (paramagnetism)PM materials, just
turn the spin polarized off?
graduate student: chen
xiaguanying university
?2009-10-02?"Duy Le" <ttduyle at gmail.com> ???
Oh, I see what you meant now. Diamagnetic materials are either AF or FM. Just
do spin polarized calculation with starting_magnetization. I don't see any
different between diamagnetic VS. AF/FM unless you have them in external
magnetic file.
2009/10/1 xirainbow <nkxirainbow at gmail.com>
Dear Chen:
You can use " nspin = 2 , starting_magnetization(1) =
1.0,starting_magnetization(2) = -1.0,".
Then PWscf will change magnetization during scf or relaxation calculation.
If the start state is antiferromagnetic state(zero initial magnetization), the
scf result would be zero magnetization(antiferromagnetic or paramagnetic).
2009/10/2 duchl06 <duchl06 at 163.com>
thanks every one's reply!
hi, Hui Wang
the example you supplied is a calculation for a antiferromagnetic material, i
mean how to set the start magnetic moment for the diamagnetic material,
best regards!
graduate student: chen
xiaguanying university
?2009-10-02?xirainbow <nkxirainbow at gmail.com> ???
Dear Chen?
> but i really donot know how to set up a cell for the diamagnetic material,
> and how to set >the start magnetic moment?
Hear is an example about graphene ribbon antiferromagnetic calculation.
Remember: different "starting_magnetization" atoms are treated as totally
different atoms.
Input file:graphene.rx.in
&CONTROL
calculation = 'relax' ,
..................
/
&SYSTEM
ibrav = 8,
celldm(1) = 4.67689278,
celldm(2) = 8.623989813,
celldm(3) = 4.048794087,
....................
nat = 12,
ntyp = 2,
nspin = 2 ,
starting_magnetization(1) = 1.0,
starting_magnetization(2) = -1.0,
/
&ELECTRONS
...................
/
&IONS
....................
/
ATOMIC_SPECIES
C1 12.00000 C.pbe-rrkjus.UPF
C2 12.00000 C.pbe-rrkjus.UPF
ATOMIC_POSITIONS crystal
C1 0.000000000 0.236465542 0.000000000
C2 0.500000000 0.265456486 0.000000000
C1 0.500000000 0.334092417 0.000000000
C2 0.000000000 0.366772814 0.000000000
C1 0.000000000 0.433673757 0.000000000
C2 0.500000000 0.466640035 0.000000000
C1 0.500000000 0.533360168 0.000000000
C2 0.000000000 0.566326232 0.000000000
C1 0.000000000 0.633227130 0.000000000
C2 0.500000000 0.665907475 0.000000000
C1 0.500000000 0.734543349 0.000000000
C2 0.000000000 0.763534596 0.000000000
K_POINTS automatic
13 1 1 0 0 0
--
____________________________________
Hui Wang
School of physics, Nankai University, Tianjin, China
"????",????60???
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____________________________________
Hui Wang
School of physics, Nankai University, Tianjin, China
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--------------------------------------------------
Duy Le
PhD Student
Department of Physics
University of Central Florida.
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