[Pw_forum] How to set the atomic position in ESM model with QE from Yuanqing Wang

[ＷＡＮＧ ＹＵＡＮＱＩＮＧ]

Dear all,

Hi. I have some puzzles when I study the ESM example in QE. The example shown below seems that there are two slabs in one unit cell if the unit cell does not repeat in the z direction in the ESM model. I am not sure if this understanding is correct. If I just want to simulate a electrochemical cell, should the metal slab just arrange in the position with z>0 ? Thank you very much!

Best regards,

Yuanqing Wang




# scf calculation for Al(111) with ESM bc3 (vacuum-slab-metal), - charged
 &control
    calculation='scf',
    restart_mode='from_scratch',
    prefix='Al111',
    pseudo_dir = '/home/wang/Program/espresso-5.1.2/pseudo/',
    outdir= './',
    tprnfor = .TRUE.
 /
 &system
    ibrav = 0, celldm(1) = 7.653393855, 
    tot_charge = -0.005,
    nat= 7, ntyp= 1,
    ecutwfc = 20.0,
    nosym=.TRUE.
    occupations='smearing', smearing='mp', degauss=0.05
    assume_isolated='esm', esm_bc='bc3'
 /
 &electrons
    mixing_beta = 0.5
 /
ATOMIC_SPECIES
 Al  26.981538   Al.pbe-rrkj.UPF
CELL_PARAMETERS hexagonal
 0.707106781    0.000000000  0.000000000
 0.353553390    0.612372436  0.000000000
 0.000000000    0.000000000 10.000000000
ATOMIC_POSITIONS angstrom
Al 0.00000    0.00000   -7.01481
Al 0.00000    1.65341   -4.67654
Al 1.43189    0.82670   -2.33827
Al 0.00000    0.00000    0.00000
Al 0.00000    1.65341    2.33827
Al 1.43189    0.82670    4.67654
Al 0.00000    0.00000    7.01481
 K_POINTS automatic
 8 8 1 0 0 0