Re: [ESPResSo-users] Doubt regarding self propulsion and diamond lattice

[Peter Košovan]

You can use the diamond command as many times as you like. Note that it is nothing else but a shortcut for multiple calls to part command. But I think it always starts from PID 0, so if you already have particles with the given IDs, they probably get overwritten. Noone can tell what is going wrong in your script if we cannot read it.

With best regards,

peter

On Thu, Oct 27, 2016 at 4:16 PM, Nairhita Samanta <address@hidden> wrote:

Hi!

Thank you very much Peter and Joost for replies. I understood a bit, but I wanted to clarify few more things.

#1 (Self propulsion)

At first one thing which I want to confirm is that in case of self propulsion if no quaternion is specified then the particle will always move in the direction of that particular axis which was directed along z-axis in zero time. However if that particular axis reorient itself to some other axis (say x axis) due to thermal fluctuation, then the particle will then move along x axis. Did I understand it correctly?

One more thing, as Joost mentioned no rotation is involved in self propulsion, but then why to we need to specify quaternion (if I want the particle to orient itself to some specific direction in the beginning). As far as I understand the four numbers of quaternion provide the axis and the angle in which particle will rotate.

#2 (Diamond lattice)

Can we use "diamond" command twice to create two lattices in a box? Regarding the position and interaction among the polymers I am using the normal FENE bond with usual parameters which I have used before to create polymers, still the polymer breaks even after quite a long warm up integration. I will still try to figure out the reason myself.

Thanking you.

With regards,

Nairhita

On Thu, Oct 27, 2016 at 12:14 PM, Peter Košovan <address@hidden> wrote:

Hi Nairhita,

regarding part 2 of your question: I anticipate that by "diamond lattice" you mean the diamond command that creates a polymer network. There is no upper limit on the number of particles, except for the obvious limit of the available memory of your computer. If your polymer breaks, then it is for a different reason. I recommend to carefully check the positions and interactions of your particles immediately after you set it up.

With best regards,

peter

On Thu, Oct 27, 2016 at 7:17 AM, Nairhita Samanta <address@hidden> wrote:

Hi all!

I have few questions regarding the self propulsion and diamond lattice feature in Espresso.

1. If I want the particle to be self propelled, do I need to specify any quaternion? I have noticed even without mentioning any quaternion, the particle moves fast. In that case what actually happens? Is there any rotation involved in propulsion then?

2. In case one uses a Diamond lattice, then can there be more than one lattice in the system? And Is there any upper limit on the number of monomers can be used per chain as the polymer breaks if the chain has say around 50/60 monomers.

Thanking you.

With regards,

Nairhita

--

Dr. Peter Košovan

Department of Physical and Macromolecular Chemistry

Faculty of Science, Charles University in Prague, Czech Republic

Katedra fyzikální a makromolekulární chemie

Přírodovědecká fakulta Univerzity Karlovy v Praze

www.natur.cuni.cz/chemistry/fyzchem/
Tel. +420221951290

Fax +420224919752

--

Dr. Peter Košovan

Department of Physical and Macromolecular Chemistry

Faculty of Science, Charles University in Prague, Czech Republic

Katedra fyzikální a makromolekulární chemie

Přírodovědecká fakulta Univerzity Karlovy v Praze

www.natur.cuni.cz/chemistry/fyzchem/
Tel. +420221951290

Fax +420224919752