hybrid tersoff potential Silica

Dear lammps developers,

I tried to run this script for the implementation and testing of a hybrid tersoff potential with LJ and Coulomb potential.

# ==============================================================================================================

units metal
dimension 3
boundary p p p
atom_style full

variable frame equal 50
variable output string "Silica_Sim"
variable temperature equal 300.0
variable pressure equal 1.00

pair_style hybrid/overlay lj/cut/coul/cut 6.0 tersoff
bond_style harmonic
angle_style harmonic

read_data data.silica

group Si type 1
group O type 2
group H type 3

pair_coeff * * tersoff SiO.tersoff Si O
pair_coeff 1 3 lj/cut/coul/cut 0.0140 2.160000 6.000 # Si-H
pair_coeff 2 3 lj/cut/coul/cut 0.0043 1.776900 4.000 # O-H
pair_coeff 3 3 lj/cut/coul/cut 0.0020 0.400000 1.200 # H-H

bond_coeff 1 19.3000 1.6300
bond_coeff 2 19.5140 0.9572

angle_coeff 1 2.2000 180.0000
angle_coeff 2 2.2000 109.4712
angle_coeff 3 2.2000 109.4712

# ==============================================================================================================

When I run it in ubuntu 14.04, it produces an error due to incorrect input parameters ( See below ) :

# ==============================================================================================================

units metal
dimension 3
boundary p p p
atom_style full

variable frame equal 50
variable output string "Silica_Sim"
variable temperature equal 300.0
variable pressure equal 1.00

pair_style hybrid/overlay lj/cut/coul/cut 6.0 tersoff
bond_style harmonic
angle_style harmonic

read_data data.silica
  orthogonal box = (-29 -29 -58) to (29 29 58)
  1 by 1 by 1 MPI processor grid
  reading atoms ...
  18704 atoms
  scanning bonds ...
  4 = max bonds/atom
  scanning angles ...
  6 = max angles/atom
  reading bonds ...
  22866 bonds
  reading angles ...
  42940 angles
  4 = max # of 1-2 neighbors
  6 = max # of 1-3 neighbors
  16 = max # of 1-4 neighbors
  20 = max # of special neighbors

group Si type 1
5872 atoms in group Si
group O type 2
12288 atoms in group O
group H type 3
544 atoms in group H

pair_coeff * * tersoff SiO.tersoff Si O
ERROR: Incorrect args for pair coefficients (../pair_tersoff.cpp:275)

# ==============================================================================================================

Could someone help me to solve this problem ?

Regards
Angelo

Dear lammps developers,

I tried to run this script for the implementation and testing of a hybrid tersoff potential with LJ and Coulomb potential.

# ==============================================================================================================

[...]

group Si type 1
5872 atoms in group Si
group O type 2
12288 atoms in group O
group H type 3
544 atoms in group H

pair_coeff * * tersoff SiO.tersoff Si O
ERROR: Incorrect args for pair coefficients (../pair_tersoff.cpp:275)

# ==============================================================================================================

Could someone help me to solve this problem ?

http://lammps.sandia.gov/doc/pair_hybrid.html

axel.