pair style hybrid/overlay

Dear Lammps Users,

  I am getting positive Ecoul energy upon using hybrid/overlay and
pair soft potential.

The following is my input script

pair_style hybrid/overlay lj/cut 12.0 lj/cut/coul/long/soft 2.0 0.5
10.0 10.0 12.0
bond_style harmonic
angle_style harmonic
pair_modify mix arithmetic

read_data lammps_data.dat

pair_coeff * * lj/cut 0.0 0.0
pair_coeff 1 8 lj/cut 0.1279 3.545
pair_coeff 2 8 lj/cut 0.00 0.00
pair_coeff 3 8 lj/cut 0.1743 3.740
pair_coeff 4 8 lj/cut 0.0 0.0
pair_coeff 5 8 lj/cut 0.2485 3.345
pair_coeff 6 8 lj/cut 0.2237 3.365
pair_coeff 7 8 lj/cut 0.0939 3.075
pair_coeff 8 8 lj/cut 0.2941 3.730

pair_coeff 1 9 lj/cut/coul/long/soft 0.0546 3.08 0.95
pair_coeff 2 9 lj/cut/coul/long/soft 0.00 1.4 0.95
pair_coeff 3 9 lj/cut/coul/long/soft 0.0744 3.275 0.95
pair_coeff 4 9 lj/cut/coul/long/soft 0.00 1.4 0.95
pair_coeff 5 9 lj/cut/coul/long/soft 0.106 2.88 0.95
pair_coeff 6 9 lj/cut/coul/long/soft 0.0955 2.9 0.95
pair_coeff 7 9 lj/cut/coul/long/soft 0.04 2.610 0.95

pair_coeff 1 10 lj/cut/coul/long/soft 0.0934 3.205 0.95
pair_coeff 2 10 lj/cut/coul/long/soft 0.00 1.525 0.95
pair_coeff 3 10 lj/cut/coul/long/soft 0.127 3.4 0.95
pair_coeff 4 10 lj/cut/coul/long/soft 0.00 1.525 0.95
pair_coeff 5 10 lj/cut/coul/long/soft 0.181 3.005 0.95
pair_coeff 6 10 lj/cut/coul/long/soft 0.163 3.025 0.95
pair_coeff 7 10 lj/cut/coul/long/soft 0.0685 2.735 0.95

pair_coeff 8 8 lj/cut 0.2941 3.73
pair_coeff 9 9 lj/cut/coul/long/soft 0.053654 2.8 1.0
pair_coeff 9 10 lj/cut/coul/long/soft 0.0917 2.925 1.0
pair_coeff 10 10 lj/cut/coul/long/soft 0.1569 3.05 1.0
pair_coeff 8 9 lj/cut 0.1255 3.265
pair_coeff 8 10 lj/cut 0.2148 3.39

Dear Lammps Users,

  I am getting positive Ecoul energy upon using hybrid/overlay and
pair soft potential.

​[...]​

------------------------------------------------------------
------------------
My output is

step c_mytemp PotEng KinEng Fmax E_vdwl E_coul E_pair E_bond E_angle
E_long E_tail
       0 0 -6802.3025 0 13.205609
-157.76455 860.18924 -6802.3025 1.6519924e-06 2.901221e-06
-7504.7272 0
     100 100.01 -6807.4904 39.052517 101.62033
-177.30824 856.13907 -6826.1205 18.314208 0.31585366
-7504.9513

---------------------- ------------------------------
----------------------

Can someone tell me why I am getting positive coul energy

​please read the documentation more carefully and look up what E_coul
stands for.
it is quite common to have that term positive for setups like yours with a
kspace solver.

axel.