[Pw_forum] Problem with scf convergence on Al Fe system

[tobita kazuki]

Dear all

I face a serious problem with SCF calculation.
When I try to perform SCF calculation on FeAl2, no matter what I do the results do not converge.
The value of estimated scf accuracy did not monotonic decrease.

FeAl2 have two partially occupied sites, and I substituted these sites with Fe atoms.
I have tried changing mixing_beta and starting_magnetization and also checked my structure parameters by using Xcrysden.

Can you please suggest some solutions. I included my input file below.

Best regards,
Tobita Kazuki

&control
 calculation = 'scf'
 prefix='FeAl2',
 tstress = .true.
 tprnfor = .true.
 pseudo_dir = '../pseudo',
 outdir='../work/'
/
&SYSTEM
  ibrav = 0
  celldm(1) =    9.21147
  nat = 19
  ntyp = 2
 ecutwfc = 30.0,
 ecutrho = 150,
 occupations = 'smearing'
 smearing = 'gauss'
 degauss = 0.01
 nspin = 2,
 starting_magnetization(1) = 0.0
 starting_magnetization(2) = 0.6
 
/
&electrons
 mixing_beta = 0.7
 conv_thr = 1.0d-8
/
ATOMIC_SPECIES
Al  26.9815  Al.pbe-n-kjpaw_psl.1.0.0.UPF
Fe  55.8457  Fe.pbe-spn-kjpaw_psl.1.0.0.UPF
CELL_PARAMETERS (alat)
  1.000000000000000   0.000000000000000   0.000000000000000 
  0.159949294828519   1.314439752606669   0.000000000000000 
  0.482074257527985   0.006550189020495   1.726118283151151 

ATOMIC_POSITIONS (crystal)
Fe   0.142400000000000   0.159410000000000   0.417230000000000 
Fe   0.857600000000000   0.840590000000000   0.582770000000000 
Fe   0.229700000000000   0.352700000000000   0.873180000000000 
Fe   0.770300000000000   0.647300000000000   0.126820000000000 
Fe   0.000000000000000   0.000000000000000   0.000000000000000 
Fe   0.163200000000000   0.473100000000000   0.591690000000000 
Fe   0.836800000000000   0.526900000000000   0.408310000000000 
Al   0.492300000000000   0.007800000000000   0.164900000000000 
Al   0.507700000000000   0.992200000000000   0.835100000000000 
Al   0.042700000000000   0.113500000000000   0.709800000000000 
Al   0.957300000000000   0.886500000000000   0.290200000000000 
Al   0.601500000000000   0.185300000000000   0.526200000000000 
Al   0.398500000000000   0.814700000000000   0.473800000000000 
Al   0.018900000000000   0.291600000000000   0.167700000000000 
Al   0.981100000000000   0.708400000000000   0.832300000000000 
Al   0.309500000000000   0.662900000000000   0.035700000000000 
Al   0.690500000000000   0.337100000000000   0.964300000000000 
Al   0.422100000000000   0.443800000000000   0.298100000000000 
Al   0.577900000000000   0.556200000000000   0.701900000000000 

K_POINTS {automatic}
2 2 1 0 0 0