ERROR: No pair reax/c for fix qeq/reax

Please reply to the list, not to me.

No, it is not correct. Re-read the pair hybrid doc page.

Ray

Dear Ray,
I think this will work for me. But I am not sure whether pair_coeff 1 2 none option can be used many times or not? Also I tried with both the options mentioned below but I am getting +ve potential energy in upper one. That means first option is not working. Please advise.

pair_style hybrid lj/cut 2.5 reax/c NULL
pair_coeff * * reax/c ffield.reax.BN B C H N

pair_coeff 1 2 none
pair_coeff 1 3 none
pair_coeff 2 4 none
pair_coeff 3 4 none

pair_coeff 1 3 lj/cut 1 1.0 1.5

pair_coeff 1 2 lj/cut 2 1.0 1.5
pair_coeff 2 4 lj/cut 3 1.0 1.5
pair_coeff 3 4 lj/cut 4 1.0 1.5

or

pair_style hybrid lj/cut 2.5 reax/c NULL
pair_coeff * * reax/c ffield.reax.BN B C H N

neigh_modify exclude type 1 2
neigh_modify exclude type 1 3
neigh_modify exclude type 2 4
neigh_modify exclude type 3 4

pair_coeff 1 3 lj/cut 1 1.0 1.5

pair_coeff 1 2 lj/cut 2 1.0 1.5
pair_coeff 2 4 lj/cut 3 1.0 1.5
pair_coeff 3 4 lj/cut 4 1.0 1.5

Both inputs are wrong. You only have 1 lj/cut so there no need to sequence them in pair_coeff commands.

Ray

ok. But how can I define the coeff. for different atom pairs in lj? Please correct me.

Dear RAy,
Is it correct now?

pair_style hybrid lj/cut 2.5 reax/c NULL
pair_coeff * * reax/c ffield.reax.BN B C H N

neigh_modify exclude type 1 2

neigh_modify exclude type 1 3
neigh_modify exclude type 2 4
neigh_modify exclude type 3 4
pair_coeff 1 3 lj/cut 1.0 1.5
pair_coeff 1 2 lj/cut 1.0 1.5
pair_coeff 2 4 lj/cut 1.0 1.5
pair_coeff 3 4 lj/cut 1.0 1.5

Dear Dr Ray,
Please correct me if I am wrong

pair_style hybrid lj/cut 2.5 reax/c NULL

pair_coeff * * reax/c ffield.reax.BN B C H N

neigh_modify exclude type 1 2

neigh_modify exclude type 1 3
neigh_modify exclude type 2 4
neigh_modify exclude type 3 4

pair_coeff 1 3 lj/cut 1.0 1.5
pair_coeff 1 2 lj/cut 1.0 1.5
pair_coeff 2 4 lj/cut 1.0 1.5
pair_coeff 3 4 lj/cut 1.0 1.5