Hello Everyone,
I am new user or VASP. I want to calculate ground state energy of Gaseous molecules of H2, HCl and H2O. As i test case i have created xyz file of H2 molecule and using VESTA software i have created POSCAR file. I did the geometry optimisation and i got the energy(without entropy) of H2 -15.9325 eV. The POSCAR file has H2 molecule in 1x1x1 Angstrom. I have changed the cell size by 10x10x10 and after optimisation i got energy (without entropy) = -0.05844729 eV.
I want to know which one is true and is it what size of box i should choose to calculate the energy of any single gas molecule?
Regards,
Amar
Energy of a gas molecule like H2
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Re: Energy of a gas molecule like H2
No, your energies are not reasonable.
In this forum you can find many examples of calculations of molecules.
E.g. H2 molecule:
http://cms.mpi.univie.ac.at/vasp-forum/ ... ecule#p555
Reasonable box size for a small molecule is 8x8x8.
Take note that energy depends on: box size, k-points set, functional, ...
In this forum you can find many examples of calculations of molecules.
E.g. H2 molecule:
http://cms.mpi.univie.ac.at/vasp-forum/ ... ecule#p555
Reasonable box size for a small molecule is 8x8x8.
Take note that energy depends on: box size, k-points set, functional, ...