I have some questions when I using lammps. I hope to simulate course grain bead spring model using lammps. However bond_style gaussian confused me. I first use gaussian function to represent Bond distribution. The gaussian function can transformed to Harmonic if factor n=1 and ignored the energy in balanced position. Just as followed picture. In simulation, unit is set in ‘real’, ‘npt’ ensemble ,298K and 1atm.
I compared the follows two.
bond_style harmonic
Bond Coeffs
1 20.474 4.81 # A-A
&&&&&&&&&&&&&&
bond_style gaussian
Bond Coeffs # gaussian
#Bond_type T(K) n a1 w1 L1
1 298 1 0.71 0.17020 4.808 # A-A
But the results are much more different. In gaussian style, some of calculate bond length is much longer than the balanced length which is 90A, compared with 4.81A
In harmonic style, there is no such result, and successfully represent the length distribution.
This confused me, could you please help me solve this problem, correct the function style and tell me the reason?
