Hi,<br><br> I seem to have a problem doing "vc-relax" with the
"starting_magnetization" initialization turned on.<br><br> I can always do a
regular "relax" with the starting_magnetization guess, and the structure
will relax with a magnetic state constrained to my *fixed* unit cell dimensions. However,
when I do a *vc-relax* with starting_magnetization set to any non-zero
value, the 2nd step in the cell relaxation always reverts to the
spin-unpolarized case (and the optimization will continue with the
spin-unpolarized case).<br>
<br> I have attached an example of this behavior for a simple
graphene nanoribbon. After the first step, the nanoribbon is magnetic
and nonzero, but the 2nd step reverts back to a non-magnetic initial
condition.<br><br>
Is there any way around this (without constraining the
magnetization to a fixed value for all steps)?<br><br>Thanks,<br>Bryan<br><br><br><br>&CONTROL<br>
calculation = 'vc-relax' ,<br> etot_conv_thr = 1.0e-4 ,<br>
forc_conv_thr = 1.0e-3 ,<br> tstress =
.true. ,<br> tprnfor = .true. ,<br> /<br> &SYSTEM<br>
ibrav = 8,<br> celldm(1) = 4.644592221,<br>
celldm(2) = 6.70720764,<br>
celldm(3) = 4.393200375,<br> nat = 10,<br>
ntyp = 4,<br> ecutwfc = 60.D0 ,<br>
nosym = .false. ,<br>
nbnd = 28,<br> nelec = 34,<br>
tot_charge = 0.000000,<br> occupations = 'smearing' ,<br>
degauss = 0.02 ,<br> smearing = 'gaussian' ,<br>
nspin = 2 ,<br> starting_magnetization(1) =
1.0,<br> starting_magnetization(2) = -1.0,<br>
starting_magnetization(3) = 1.0,<br> starting_magnetization(4) = -1.0,<br> /<br> &ELECTRONS<br>
conv_thr = 1.D-6 ,<br> mixing_beta =
0.7D0 ,<br> /<br> &IONS<br> ion_dynamics = 'bfgs' ,<br>
pot_extrapolation = 'second_order' ,<br> wfc_extrapolation =
'second_order' ,<br>
trust_radius_ini = 0.2D0 ,<br> /<br>ATOMIC_SPECIES<br>
H1 1.00000 H.pbe-rrkjus.UPF<br> C1 12.00000 C.pbe-rrkjus.UPF<br>
C2 12.00000 C.pbe-rrkjus.UPF<br> H2 1.00000 H.pbe-rrkjus.UPF<br>ATOMIC_POSITIONS
crystal<br>
H1 0.000000000 0.218692155 0.000000000 1 1 0<br>
C1 0.000000000 0.284883518 0.000000000 1 1 0<br>
C2 0.500000000 0.326062773 0.000000000 1 1 0<br>
C1 0.500000000 0.413734370 0.000000000 1 1 0<br>
C2 0.000000000 0.456468822 0.000000000 1 1 0<br>
C1 0.000000000 0.543530576 0.000000000 1 1 0<br>
C2 0.500000000 0.586265119 0.000000000 1 1 0<br>
C1 0.500000000 0.673937250 0.000000000 1 1 0<br>
C2 0.000000000 0.715116935 0.000000000 1 1 0<br>
H2 0.000000000 0.781308481 0.000000000 1 1 0<br>K_POINTS
automatic<br> 13 1 1 0 0 0