Re: [lammps-users] CNT simulation

[Mehrdad Arjmand <mehrdad.nano@gmail.com>]

Hi Steve,

Many thanks for your helps.

Would you please tell me how I should use "fix deform" to shrink the box?

I did not find anything about it in the manual. 

Did you mean that? 

for example: "fix 3 all deform" 

Please correct me.

Kind regards

Mehrdad

On Tue, Jun 8, 2010 at 8:17 PM, Mehrdad Arjmand <mehrdad.nano@gmail.com> wrote:

---------- Forwarded message ----------
From: Mehrdad Arjmand <mehrdad.nano@gmail.com>
Date: Tue, Jun 8, 2010 at 1:46 PM
Subject: Re: [lammps-users] CNT simulation
To: Steve Plimpton <sjplimp@gmail.com>


Hi Steve,

Many thanks for your helps.

Would you please tell me how I should use "fix deform" to shrink the box?

I did not find anything about it in the manual. 

Did you mean that? 

for example: "fix 3 all deform" 

Please correct me.

Kind regards

Mehrdad 

On Mon, Jun 7, 2010 at 6:26 PM, Steve Plimpton <sjplimp@gmail.com> wrote:

The huge amount of memory is likely b/c your box size has become unphysically
huge.

You can shrink/expand a box without changing atom positions if
you use the fix deform dilate no option.

Steve

On Sat, Jun 5, 2010 at 11:54 PM, Mehrdad Arjmand <mehrdad.nano@gmail.com> wrote:
> Dear steve,
> Thanks for your reply. when I use fix deform command, after a while I face
> with the huge amount of memory requested by LAMMPS and therefore it stops. I
> have tried to use box relax, but the nanotube also shrinks as the box does.
> Is there any way to contract the box size without changing nanotube?
>
> Best regards
> Mehrdad
>
> On Thu, Jun 3, 2010 at 6:45 PM, Steve Plimpton <sjplimp@gmail.com> wrote:
>>
>> If you are using fix deform remap x, then all the atoms in
>> the box dilate uniformly as the box stretches.
>>
>> Steve
>>
>> On Wed, Jun 2, 2010 at 9:44 AM, Mehrdad Arjmand <mehrdad.nano@gmail.com>
>> wrote:
>> > Thanks for your reply. If I want to know the exact deformation and
>> > deformation rate of one end atoms, Which one is more accurate?
>> > What is the difference between them?
>> >
>> > On Wed, Jun 2, 2010 at 6:44 PM, Steve Plimpton <sjplimp@gmail.com>
>> > wrote:
>> >>
>> >> If the remap option on fix deform is set to x (the defuault), then
>> >> the atoms deform with the box.  The velocity command just sets
>> >> the velocity of some atoms.  If you did this to the end atoms,
>> >> it could be similar to fix deform, but not exactly the same.
>> >>
>> >> Steve
>> >>
>> >> On Wed, Jun 2, 2010 at 7:09 AM, Mehrdad Arjmand
>> >> <mehrdad.nano@gmail.com>
>> >> wrote:
>> >> > Dear friends,
>> >> >
>> >> > I have modeled a CNT and want to put it under tension. I want to ask
>> >> > you:
>> >> > Firstly, whether "fix deform" command that changes the box size with
>> >> > a
>> >> > constant strain rate (e.g. 0.1), changes the nanotube's length with
>> >> > the
>> >> > same
>> >> > rate or not.
>> >> > Secondely, I want to ask you if "velocity" does the same job as "fix
>> >> > deform".
>> >> >
>> >> > Thanks
>> >> > Mehrdad
>> >> >
>> >> >
>> >> >
>> >> > ------------------------------------------------------------------------------
>> >> >
>> >> >
>> >> > _______________________________________________
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>> >> > lammps-users@lists.sourceforge.net
>> >> > https://lists.sourceforge.net/lists/listinfo/lammps-users
>> >> >
>> >> >
>> >
>> >
>
>