Dear all

I want to have a pressure distribution (pressure profile) of a group of atoms(here ‘flow’ group). I

use the following way to do this.

units real

compute peratom flow stress/atom

variable press1 atom -(c_peratom[1]+c_peratom[2]+c_peratom[3])/3

fix profile flow ave/spatial 1 100000 1000000 x lower 1 y lower 1 z lower 1 v_press1 units box ave running file MyProfile.txt

In the *post processing procedure*, i divide the *v_press1* value by the *volume* of the corresponding Bin and the average Number of the atoms in that Bin.I.e. v_press1/(N_count * Bin_volume) [here the Bin_volume is 1].

So i have an average pressure for every Bin and a pressure distribution.

please tell me that if the above described way is true or not?

Many Thanks in advance

mahdi

mahdi sahebi

phd student

Isfahan university of technology

Dear all

I want to have a pressure distribution (pressure profile) of a group of

atoms(here 'flow' group). I

use the following way to do this.

units real

compute peratom flow stress/atom

variable press1 atom -(c_peratom[1]+c_peratom[2]+c_peratom[3])/3

fix profile flow ave/spatial 1 100000 1000000 x lower 1 y lower 1 z lower 1

v_press1 units box ave running file MyProfile.txt

In the post processing procedure, i divide the v_press1 value by the volume

of the corresponding Bin and the average Number of the atoms in that

Bin.I.e. v_press1/(N_count * Bin_volume) [here the Bin_volume is 1].

So i have an average pressure for every Bin and a pressure distribution.

please tell me that if the above described way is true or not?

please note that this mailing list is not an input file approval

service. would you be willing to debug other people's inputs. and by

showing just a small part, how can we know that the rest is done

correctly? so you have to come up with a strategy to validate your

approach by yourself. that is just good practice anyway. what does it

help you, if somebody here says "yes, it is correct", when it would

turn out to be wrong, because that person didn't know better or

overlooked a mistake? how can you know what and whom to trust (but

yourself)?

so why don't you just test it on a simulation of a homogeneous system

without a pressure gradient, where each bin should have (on average)

the same pressure as the global pressure? and start with one bin (i.e.

all of the system) and gradually increase the number of bins/slices to

the desired resolution to see what kind of averaging and simulation

length is required to get well converged results and then work in

steps toward your real target system.

axel.