Too small values for pe, ke and etot using thermostyle

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Respected Lammps Users, I am using lammps 2023 mpi windows version. I am wetting the graphite substrate with iron and getting very small potential energy, kinetic energy and total energy using thermostyle thermo_style custom step etotal ke pe in orders of -0.09 ev while using compute peatom all pe/atom and then print its output as the reduce sum in thermostyle also give exactly the same value which is very very less but which I print it using the fix for sum reduce and open the fix print file it shows big values confirming the decimal places to some literature but even then there are number of sensitive parameters to calculate the interaction energy between iron and graphite. The command used are as kindly assist

    compute peg   all  reduce sum c_peatom
     variable pet equal c_peg
     thermo_style custom step  pe c_peg
     fix statdump2a all print 2 "${pet}" screen no file dump.stat2```
     the values come out for `pe and c_peg` are exactly same in order 0.09 ev while `${pet}`  comes   in order of `16734.2194 ev`? why
which command is best suitable to measure the interaction energy between the two is compute intEnergy iron group/group graphite right to use?
Thanks for cooperation
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Can you elaborate more? I don’t understand your question very well:

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Dear Hothello, using thermostyle command with thermostyle variables calculating the total potential energy of the system using pe containing iron which is wetting graphite substrate which has defined units in ev; the values comes out in ranges of -0.09 ev and fluctuates with time steps but upto two decimal places which is very small and false according to literature.
But when compute command is used to measure peratom potential energy and sum it after that output it in thermostyle variables with c_peg then both directly using pe and define peratom sum and then introduce variable and calculate in the thermostyle give same results with range -0.09; this is value of one timestep but all timestep pe value are small and less.
But if the compute sum variable ${pet} is introduced in fix command and generate a file gives huge values like 16734 in order of 10 thousands every timestep close to literature.
So why the same variable gives two different results in thermostyle and fix command for fix command it is further defined by equal but are equal variable pet equal c_peg.
Secondly if the interaction potential energy between these two types of atoms are required to be calculated then is this way fine of use group/group command?
Thanks

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You better read the forum guidelines. I still have no clue of what you are doing, and I have no interest in finding it out. So please: read the forum guidelines, write a decent post providing context and details, and read your message two times before posting it.

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