[lammps-users] Question on Pair_hybrid

Dear LAMMPS users,

Today, I encountered a problem. This is about pair_hybrid command.

The part of my input script is shown as follows;

<case 1>
pair_style hybrid eam lj/cut 5.0
pair_coeff 2 2 eam Ni_u3
pair_coeff 1 1 lj/cut 0.5 1.2
pair_coeff 1 2 lj/cut 0.5 1.2

<case 2>
pair_style hybrid lj/cut 5.0 tersoff/zbl
pair_coeff 1 1 lj/cut 0.5 1.2
pair_coeff 1 2 lj/cut 0.5 1.2
pair_coeff 2 2 Sic.tersoff.zbl NULL Si

<case 3>
pair_style hybrid table spline 1001 eam
pair_coeff 1 1 ZBL.ArAr ZBL_ArAr 5.5
pair_coeff 1 2 ZBL.ArSi ZBL_ArSi 5.5
pair_coeff 2 2 eam Ni_u3

<case 4>
pair_style hybrid table spline 1001 tersoff/zbl
pair_coeff 1 1 ZBL.ArAr ZBL_ArAr 5.5
pair_coeff 1 2 ZBL.ArSi ZBL_ArSi 5.5
pair_coeff 2 2 SiC.tersoff.zbl NULL Si

Case 1 was made based on the example in manual and case 4 is my final object. 2 and 3 is a combination of case 1 and 4.
Interestingly, only for the case 1 was done without problem, but others show an error message of “ERROR: Pair coeff for hybrid has invalid style”.
I tried as many as I could try but in vain. I really appreciate if anyone tells me the solutions or indicates my faults.

Thanks in advance,

SP

2009/10/5 Sang-Pil Kim <[email protected]…24…>

Dear LAMMPS users,

Today, I encountered a problem. This is about pair_hybrid command.

The part of my input script is shown as follows;

<case 1>
pair_style hybrid eam lj/cut 5.0
pair_coeff 2 2 eam Ni_u3
pair_coeff 1 1 lj/cut 0.5 1.2
pair_coeff 1 2 lj/cut 0.5 1.2

<case 2>
pair_style hybrid lj/cut 5.0 tersoff/zbl
pair_coeff 1 1 lj/cut 0.5 1.2
pair_coeff 1 2 lj/cut 0.5 1.2
pair_coeff 2 2 Sic.tersoff.zbl NULL Si

<case 3>
pair_style hybrid table spline 1001 eam
pair_coeff 1 1 ZBL.ArAr ZBL_ArAr 5.5
pair_coeff 1 2 ZBL.ArSi ZBL_ArSi 5.5
pair_coeff 2 2 eam Ni_u3

<case 4>
pair_style hybrid table spline 1001 tersoff/zbl
pair_coeff 1 1 ZBL.ArAr ZBL_ArAr 5.5
pair_coeff 1 2 ZBL.ArSi ZBL_ArSi 5.5
pair_coeff 2 2 SiC.tersoff.zbl NULL Si

Case 1 was made based on the example in manual and case 4 is my final object. 2 and 3 is a combination of case 1 and 4.
Interestingly, only for the case 1 was done without problem, but others show an error message of “ERROR: Pair coeff for hybrid has invalid style”.
I tried as many as I could try but in vain. I really appreciate if anyone tells me the solutions or indicates my faults.

You forgot to include the pair style for the tersoff style in some of your pair_coeff statements. You need to use "pair_coeff x y tersoff . . . " just like you used “pair_coeff x y eam” and “pair_coeff x y lj/cut.”

–AEI