Hi,

I am trying to user pair_style hybrid overlay as below

pair_style hybrid/overlay table spline 500 coul/cut 10.0

pair_coeff 1*2 1*2 table AA.txt Nonbonded_AA

pair_coeff 1*2 3*8 table AB.txt Nonbonded_AB

pair_coeff 3*8 3*8 table BB.txt Nonbonded_BB

pair_coeff 1*2 9 table AC.txt Nonbonded_AC*

pair_coeff 38 9 table BC.txt Nonbonded_BC

pair_coeff 9 9 table CC.txt Nonbonded_CC

pair_coeff 1*2 10 table AD.txt Nonbonded_AD*

pair_coeff 38 10 table BD.txt Nonbonded_BD

pair_coeff 9 10 table CD.txt Nonbonded_CD

pair_coeff 10 10 table DD.txt Nonbonded_DD

pair_coeff 9 9 coul/cut

pair_coeff 9 10 coul/cut

pair_coeff 10 10 coul/cut

such that my atom types 1-8 have zero charge and 9 is -1 and 10 is +1.

When, I write the pair_energy using pair_write, all the energy profile come out to be same. So, we believe, hybrid/overlay is adding the energies for uncharged atoms as well.

I am wondering if you could let me know if I am doing something wrong.

Thanks,

Anupriya

Hi,

I am trying to user pair_style hybrid overlay as below

pair_style hybrid/overlay table spline 500 coul/cut 10.0

pair_coeff 1*2 1*2 table AA.txt Nonbonded_AA

pair_coeff 1*2 3*8 table AB.txt Nonbonded_AB

pair_coeff 3*8 3*8 table BB.txt Nonbonded_BB

pair_coeff 1*2 9 table AC.txt Nonbonded_AC

pair_coeff 3*8 9 table BC.txt Nonbonded_BC

pair_coeff 9 9 table CC.txt Nonbonded_CC

pair_coeff 1*2 10 table AD.txt Nonbonded_AD

pair_coeff 3*8 10 table BD.txt Nonbonded_BD

pair_coeff 9 10 table CD.txt Nonbonded_CD

pair_coeff 10 10 table DD.txt Nonbonded_DD

pair_coeff 9 9 coul/cut

pair_coeff 9 10 coul/cut

pair_coeff 10 10 coul/cut

such that my atom types 1-8 have zero charge and 9 is -1 and 10 is +1.

When, I write the pair_energy using pair_write, all the energy profile

come out to be same. So, we believe, hybrid/overlay is adding the energies

for uncharged atoms as well.

You have to be more clear in describing your question. What energy

profile? The same as what? Adding what energies to uncharged atoms? Why

is it wrong?

Please note hybrid/overlay does add all energy contributions from all pair

styles.

Ray

Thank you for getting back to me. I should have explained my issue in more detail in my previous email. So, here it goes.

In my simulation, I would like to have the nonbonded energies to have two components - pair energy to be read from pair_table and coulomb energy which comes from coulomb/cut. This I am trying to implement using hybrid/overlay.

Before using hybrid/overlay, my energies for A,B,C andD atom types and their crossterm look like (before.png). Now, A and B doesnâ€™t have charge and C and D has -1 and +1 charge respectively. So, after using hybrid/overlay with coul/cut, energies of A and B should remain same (i.e. AA, AB, BB, AC, BC, BD, AD should not change), however, when I write the energies using pair_write, I get energy profiles as (after.png). So, all energy profile looks same. I expect CC, DD and DC to be like (expected.png).

I am having the same trouble if I use hybrid/overlay with coul/long. It seems that when used with hybrid/overlay, charges are not read from data file instead just taken +1 for all A,B,C,D.

Please let me know if you have any questions.

Thanks,

Anupriya

All I can say with the information you provided are:

- LAMMPS should do what you told it to do,
- Nobody can know what really happens without seeing your input files, and
- If you believe there is a bug with hybrid/overlay, provide a simple input deck

Ray