Hi, 

Do you want to perform calculations on magnetic materials using QE? 

read input file description for pw.x (http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html)

a lot of information available in PW_forum or you may get it by googling...

Give a look at the following links

http://www.fisica.uniud.it/~giannozz/QE-Tutorial/tutorial_magn.pdf

http://users.aims.ac.za/~sandro/files/tutorial_magn.html

Thanx manoharan but i should apply a magnetic field for example 2 tesla on magnetite, how i can?

Hello.

Well as far I know, there is no built in mechanism for simply applying external magnetic field in way you would expect. Instead, there are some input keys, that can force magnetic moments to be aligned along the 'z' axis, or (when doing noncollinear magnetism) you can specify also it's direction.

For simplified 'simulation' of external magnetic field you can use total_magnetization that forces system to be magnetic. For the latter case constrained_magnetization (with lambda and fixed magnetization keywords) can be used (note, that when constrained_magnetization is used with type 'total', you must use noncollinear calculation and suitable pseudopotential files).   

Use the first link provided by Manoharan for description of specified keywords, and then try with some very simple system to check, if you get what you expect.

Regards,

Konrad

thanx konard

plz look at the end of my scf.out:

why magnetic field is per Rydberg?and how can i convert that to Tesla?

.....

total energy = -253.04759495 Ry

Harris-Foulkes estimate = -253.04758781 Ry

estimated scf accuracy < 0.00000452 Ry

The total energy is the sum of the following terms:

one-electron contribution = -127.46773250 Ry

hartree contribution = 72.38794581 Ry

xc contribution = -27.02379306 Ry

ewald contribution = -170.94380974 Ry

smearing contrib. (-TS) = -0.00020546 Ry

total magnetization = 5.00 Bohr mag/cell

absolute magnetization = 5.00 Bohr mag/cell

Magnetic field = 0.3285968 Ry????????????????????????????????????????

convergence has been achieved in 6 iterations

.....

and my scf.in:

&CONTROL

calculation = "scf",

prefix = "Fe",

pseudo_dir = "./",

outdir = "./TMP",

/

&SYSTEM

ibrav = 3,

celldm(1) = 5.45,

constrained_magnetization = "total",

nspin=2,

fixed_magnetization (3) = 5,

nat = 1,

ntyp = 1,

ecutwfc = 28,

ecutrho = 300,

starting_magnetization(1)=0.5

occupations='smearing'

smearing='mp'

degauss=0.015

lambda=1

/

&ELECTRONS

conv_thr = 1.D-5,

mixing_beta = 0.3D0,

/

&IONS

/

ATOMIC_SPECIES

Fe 55.845 Fe.pbe-sp-van_ak.UPF

ATOMIC_POSITIONS (angstrom)

Fe 0.000000000 0.000000000 0.0

K_POINTS automatic

7 7 7 1 1 1

Hello again.

It seams, that you have made a few mistakes in your input. But before explaining those mistakes, can I know how much experience do you have in DFT calculations? Did you perform relax calculation and (even before) did you tested your system for convergence?

And as I remember this magnetization is in:  (e_f_up-e_f_dn)/2 in Rydbergs, but try to find it in documentation.