Using two pair_styles together

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1

Hello,
I 'm trying to use two pair styles lj/cut and coul/wolf together as follows:

pair_style hybrid/overlay lj/cut 8.5 coul/wolf 0.2 10.0
read_data mstruc.lammps05

but lammps gives this error:
Incorrect args for pair coefficients (pair_coul_wolf.cpp:187)

However when I use the following it works fine;

pair_style lj/cut/coul/cut 8.5 10.0
read_data mstruc.lammps05

Thanks in advance,

Meysam

2

Hello,
I 'm trying to use two pair styles lj/cut and coul/wolf together as follows:

pair_style hybrid/overlay lj/cut 8.5 coul/wolf 0.2 10.0
read_data mstruc.lammps05

but lammps gives this error:
Incorrect args for pair coefficients (pair_coul_wolf.cpp:187)

However when I use the following it works fine;

pair_style lj/cut/coul/cut 8.5 10.0
read_data mstruc.lammps05

when you switch to a hybrid pair style, the format
for providing the pair coefficients changes. each set
of parameters needs to be prefixed with the style it
applies to. i am not sure if you can use the Pair Coeffs
section in a data file at all with that, but for certain
not without changes.

axel.

3

The format of pair coefficients in the input structure data is:

Pair Coeffs

1 0.0000000000 0.0000000000
2 0.1554164124 3.1655200879
3 0.1554164124 3.1655200879
4 0.1554164124 3.1655200879
5 0.0000009030 5.2643258688
6 0.0000013297 4.2713219316
7 0.0000018402 3.3019566252
8 0.1300999871 2.3500126639
9 0.1554164124 3.1655200879
10 0.1554164124 3.1655200879
11 0.0000000000 0.0000000000
12 0.0559124714 2.8001051606
13 0.1596834563 3.0281188079

Please tell me how I should change them.

4

The format of pair coefficients in the input structure data is:

Pair Coeffs

   1 0.0000000000 0.0000000000
   2 0.1554164124 3.1655200879
   3 0.1554164124 3.1655200879
   4 0.1554164124 3.1655200879
   5 0.0000009030 5.2643258688
   6 0.0000013297 4.2713219316
   7 0.0000018402 3.3019566252
   8 0.1300999871 2.3500126639
   9 0.1554164124 3.1655200879
  10 0.1554164124 3.1655200879
  11 0.0000000000 0.0000000000
  12 0.0559124714 2.8001051606
  13 0.1596834563 3.0281188079

Please tell me how I should change them.

RTFM.

a.

5

When questions like the one below are posted, responses like the one
just offered by Axel are well deserved. Those who are turning to the
list as a vehicle to solve their assignments without first trying
their best do nothing but compromise the quality of this service by
potentially discouraging knowledgeable people from participating due
to the trivial nature of the questions being asked. Please community,
keep that in mind at all times.
Carlos

6

If you have one pair coeff assigment per I/I atom type you
can define pair coeffs for the pair hybrid style in the
data file. The syntax for doing so is essentially the
same as in the input script. It is a different syntax that
the usual pair coeff command, and is described on the
pair hybrid doc page. In your case you appear to be
using hybrid/overlay, which means you want to assign
multiple pair coeff commands to each pair of atom
types. You have to do that in the input script.

Steve

7

Thank you Steve.