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Re: [lammps-users] Pair_style hybrid
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Re: [lammps-users] Pair_style hybrid


From: Kousika A <kousika12@...24...>
Date: Thu, 24 Aug 2017 15:13:31 +0530

Thank you Michal. I have few more doubts. If I am using a hybrid potential, how to check the reliability of the potential for that system? Other than it's lattice parameter and bulk modulus, do we need to check any other things?
I have got results for lattice parameter and bulk modulus comparable with the reported values (@0K) But when I am bringing the system to 300K, the potential fails. How to fix this? 

Thanking you,
Kousika

On Wed, Aug 23, 2017 at 8:22 PM, Michał Kański <michal.kanski@...2460...> wrote:

This is the way LAMMPS is designed – pair_style is defined for an entire system and if you want to utilize different potentials at once you have to use pair_style hybrid.

 

Michal

 

From: Kousika A
Sent: środa, 23 sierpnia 2017 15:36
To: Michał Kański
Cc: LAMMPS Users Mailing List
Subject: Re: [lammps-users] Pair_style hybrid

 

Thank you Michal. But I am using single pairstyle for each pair. For some pairs only Morse and for others, only coul like that. So how come overwritten will happen?

 

 

 

On Wed, Aug 23, 2017 at 6:37 PM, Michał Kański <michal.kanski@...2460...> wrote:

In the first one each pair_style command overwrites earlier ones. The second one allows for using different pair_styles alongside.

 

Michal

 

From: Kousika A
Sent: środa, 23 sierpnia 2017 14:42
To: LAMMPS Users Mailing List
Subject: [lammps-users] Pair_style hybrid

 

Dear lammps users,

                                 I am modeling a quaternary system. I am using two different pair styles, Morse and coul/wolf for the interactions. What is the difference if I am giving the interactions separately like in (1) or giving using hybrid command as in (2)

 

(1)

pair_style morse 6.0 

pair_coeff 1 3 0.5799 2.232 2.737 6  #Ba-O 

pair_coeff 1 4 0.858 2.33 2.677 6   #Ba-N

  

pair_coeff 2 3 2.3667 2.087 1.855   #Ta-O

pair_coeff 2 4 1.7369 2.16 1.987   #Ta-N

#pair_coeff 3 3 5.116 2.6796 1.208 # O-O

#pair_coeff 4 4 9.904 2.85 1.08 #N-N

#pair_coeff 3 4 6.623 2.83 1.159 #O-N

 

pair_style coul/wolf 0.3367 10

pair_coeff 1 1 

 

pair_style coul/wolf 0.402 10

pair_coeff 1 2 

 

pair_style coul/wolf 0.4975 10

pair_coeff 2 2 

 

pair_style coul/wolf 0.913 10

pair_coeff 3 3 

 

pair_style coul/wolf 0.888 10

pair_coeff 4 4 

 

pair_style coul/wolf 0.507 10

pair_coeff 3 4 

 

 

(2)

 

pair_style hybrid morse 10.0 coul/wolf/mod 0.3367 10 coul/wolf/mod 0.402 10 coul/wolf/mod 0.4975 10 coul/wolf/mod 0.913 10 coul/wolf/mod 0.888 10 coul/wolf/mod 0.507 10

pair_coeff 1 3 morse 0.5799 2.232 2.737  #Ba-O 

pair_coeff 1 4 morse 0.858 2.33 2.677    #Ba-N

  

pair_coeff 2 3 morse 2.3667 2.087 1.855   #Ta-O

pair_coeff 2 4 morse 1.7369 2.16 1.987   #Ta-N

 

pair_coeff 1 1 coul/wolf/mod 1

 

pair_coeff 1 2 coul/wolf/mod 2

 

pair_coeff 2 2 coul/wolf/mod 3

 

pair_coeff 3 3 coul/wolf/mod 4

 

pair_coeff 4 4 coul/wolf/mod 5

 

pair_coeff 3 4 coul/wolf/mod 6

 

Kindly clarify this.

 

Thanking you,

Kousika