Re: [ESPResSo] Help with configuring espresso input

[Limbach, Hans Joerg, LAUSANNE, Food Materials]

Hi Michael,

 

I think there is no special command for brushes, but you can build a brush yourself with help of the polymer command:

 

Step 1: Setup the brush backbone:

    polymer 1 backbone_length bond_length [other options see user guide]

 

Step 2:  Setup the brushes   

    Loop over monomers in backbone { i = 0 to backbone_length-1

        2a: ger the position of a monomer in the backbone:

            set tmp_pos [part $i print pos]

        2b: set up the next brush

            set pid [expr backbone_length + (i*brushlength)]

            polymer 1 brush_length bond_length   start pid    pos $tmp_pos

}

 

Note that the above is just schematic and not direct tcl code.

 

These things are not implemented by purpose as everybody will need slightly different things. But as you can see above it is rather simple to build new things out of the existing commands and a little bit of tcl script. Moreover you are more then welcome to write a gerneric polymer_brush command and contribute in this way to the Espresso package.

 

Best regards,

Hanjo

 

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From: address@hidden [mailto:address@hidden On Behalf Of Michael Winokur
Sent: mardi, 7. juillet 2009 22:52
To: address@hidden
Subject: [ESPResSo] Help with configuring espresso input

Hello all,

I've just begun to look at espresso in earnest.

Could someone kindly suggest how one inputs a copolymer brush type molecule? As far as I can tell in the user guide the "polymer" input just specifies a single monomer unit.

Thanks for any help you can give.

Michael
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/ Michael Winokur
/ Department of Physics
/ University of Wisconsin Email:address@hidden
/ Madison, WI 53706
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