Dear all,
I want to simulate heptan with opls or charmm force field. First I put 100 molecules of heptan in a cubic box, but total energy and potential energy became positive. Then I simulated just 1 molecule of heptan in a cubic box, and again toatal energy and potential energy were positive.
I even tested example of lammps that contains water and methane molecules. I made some changes in the input and data file to simulate just methane molecules. I attached the files, but energies became positive again.
Please help me in this regards, I really need your help.
data.lmp (1.24 KB)
in.fdti01.lmp (691 Bytes)
log.lammps (12 KB)
Dear all,
I want to simulate heptan with opls or charmm force field. First I put 100
molecules of heptan in a cubic box, but total energy and potential energy
became positive. Then I simulated just 1 molecule of heptan in a cubic box,
and again toatal energy and potential energy were positive.
why is that a bad thing?
I even tested example of lammps that contains water and methane molecules.
I made some changes in the input and data file to simulate just methane
molecules. I attached the files, but energies became positive again.
there is nothing fundamentally wrong with this input deck, outside that it
doesn't make much sense to simulate an isolated methane molecule as such.
Please help me in this regards, I really need your help.
you obviously need help that goes beyond the scope of this mailing list
and your problems go deeper than just how to use LAMMPS. you need help with
understanding MD simulations and classical force fields. this, however, is
not something people can teach you by answering some e-mails. you need to
read/understand text books and you need a personal teacher/tutor.
axel.