Hi everyone,

    I am doing a molecular dynamics simulation under the influence of a static external electric field, I dont know how to apply it.

I learn from stephen that electric field tools are implemented in a Tcl script, how to edit the script?Is it like below in Polyethylene.inp

#BIOSYM btcl 3

#

#  Input File For Discover Generated By Materials Studio

#  Input Client Model Document: E:\\MS\\example5 Files\\Documents\\Polyethylene.xsd

#  Job: [saved] - Polyethylene Disco Dynamics

#

  autoEcho off

#

# Begin Forcefield Section

  begin forcefield = compass

#

# Nonbond section:

  forcefield nonbond \\

      -separate_coulomb \\

    vdw \\

    summation_method = atom_based \\

      cutoff = 9.50 \\

      spline_width = 1.00 \\

      buffer_width = 0.50 \\

    coulomb \\

    dielectric_value = 1.0000

# End Forcefield Section

#

# Dynamics Section:

  dynamics \\

    time = 300000.00 \\

    timestep = 1.00 \\

    initial_temperature = 450.00 \\

    ensemble = NVT \\

    temperature_control_method = velocity_scaling \\

    temperature_window = 15.00 \\

    temperature = 450.00 \\

    deviation = 5000.00 \\

    execute frequency = 5000.00 \\

      command = {print history}

    efield {{ 5e9 0 0 }}

    efield_off

just add "

efield {{ 5e9 0 0 }}

    efield_off"  in the last?

but the results are not different from those without the two sentences.

can you gave me some advices?

thanks

jordon