# Compute pe/tally not working?

Hello,

I am trying to calculate the per atom scalar (the contributions of the single atom to the global scalar). When I use my test script

Hello,

I am trying to calculate the per atom scalar (the contributions of the single atom to the global scalar). When I use my test script

[...]

The sum of c_Ta_O_pe is -58 and the sum of c_Ta_O_pe is -8609. I assumed that sum of c_Ta_O_pe would equal the total energy of my system as my only non-zero potential is for 1-2. I also don't understand what c_Ta_O_pe is supposed to represent.

you are discounting the contribution from coulomb in your
consideration. with setting the buckingham interaction energy to zero,
you do not affect the coulomb interactions. unless all charges would
be set to zero, that is, but then you would be using pair style buck.

c_Ta_O_pe is the contribution of the buckingham potentials,
c_Ta_O_pe is the contribution from the coulomb potential. The
documentation is incomplete.

try outputting "evdwl" and "ecoul" in your thermo output. those are
the totals of the buckingham and coulomb energy contributions (of the
whole system) individually.

If I change the potential from buck/coul/cut to lj/cut my results are

lj/cut does not consider charges, hence c_Ta_O_pe is always zero.

Step Temp PotEng KinEng TotEng Press Volume Density
0 0 -32.666011 0 -32.666011 -8128.97 12876.591 6.6575097
Loop time of 1.11759e-06 on 1 procs for 0 steps with 975 atoms

[...]

The sum of c_Ta_O_pe is -32.666 (same as the energy I calculated) and the sum of c_Ta_O_pe is 0.

I am using lammps-stable-12Dec2018 made with intel/2018 and openmpi/3.1.2
Any help would be greatly appreciated and I would be happy to give more information.

so far i don't see anything conclusive pointing to a problem with
compute pe/tally.

axel.