Molecular Dynamics (using pw.x)

We will start from the relaxation calculation, and use the relaxed structure for md calculation. Below in the input file for md calculation:

src/H2O-md-pw/pw.md.h2o.in

&control
    calculation  = 'md'
    restart_mode = 'from_scratch'
    prefix       = 'h2o'
    outdir       = './tmp/'
    pseudo_dir   = '../pseudos/'
    tstress      = .true.
    tprnfor      = .true.
!   about 1 fs; 1 a.u. = 0.048378 fs
    dt           = 20
    nstep        = 100
/

&system
    ibrav     = 1
    celldm(1) = 15
    nat       = 3
    ntyp      = 2,
    ecutwfc   = 40
    nosym     = .true.
/

&electrons
    conv_thr = 1e-8
/

&ions
    pot_extrapolation = 'second-order'
    wfc_extrapolation = 'second-order'
    ion_temperature   = 'initial'
    tempw             = 300
/

ATOMIC_SPECIES
 H  1.00784  H_ONCV_PBE-1.0.oncvpsp.upf
 O  15.999   O.pbe-n-kjpaw_psl.0.1.UPF

! relaxed structure
ATOMIC_POSITIONS (angstrom)
O             5.0000068025        4.8011777008        4.9999667189
H             4.9999962341        5.3994076541        5.7670041300
H             4.9999969634        5.3994146451        4.2330291511

K_POINTS automatic
  1 1 1 0 0 0

Quantum ESPRESSO output file can be loaded in Xcrysden for visualization.