Hi,
In a system under study, I have some Al ions, and I want to measure the interaction of ions with each other using compute group/group command.
I am getting negative col energy and positive value for pair interactions. I was wondering if negative value for coulombic interactions between positively charged ions is correct/possible? Do you have any idea about this? Thank you.
Input file:
boundary p p p
units real
atom_style full
bond_style harmonic
angle_style harmonic
dihedral_style opls
improper_style harmonic
pair_style soft 12
pair_style lj/cut/coul/long 10.0 10.0
read_data data.data
group Al type 3
set type 3 charge +3.000000
pair_modify mix geometric tail yes table 12
compute Int_Col_Al_Al Al group/group Al pair no kspace yes boundary yes
compute Int_Pair_Al_Al Al group/group Al pair yes kspace no boundary yes
fix Int_Al_Al all ave/time 5 50 500 c_Int_Col_Al_Al[0] c_Int_Pair_Al_Al[0] file tmp_Al_Al.Int