hydrogen not detcted during calculation

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ag9xc · #1 Post by **ag9xc** » Wed Nov 19, 2008 3:31 pm

Hi all,

I am trying to do some simple energy optimisation calculations using VASP. I am getting a very weird error. I am running acetylene, vinyl, ethyl gas phase calculations. For all of them the code ran and converged. But when I look at the results, the energy values are not correct. The reason for that is there are no hydrogen atoms in the corresponding CONTCARS. Basically, its just detecting carbon and no hydrogens. I tried ethylene on Pt(111) too and got similar problem. There are Pt and C atoms in CONTCAR, but no H atoms. When I do "grep US POTCAR" it shows hydrogen. Also, the calculation converges. Hence I am not able to figure out what is going on. Can somebody please give some insights?

Thanks,
Amit

#2 Post by **admin** » Wed Nov 19, 2008 4:03 pm

have you defined the hydrogen atoms in POSCAR ( the line giving the numbers of atoms per tyre has to have 3 numbers, giving the numbers of Pt, C and H atoms, respectively, depending on the order they are read from POTCAR)?
VASP does not change the atoms and atom numbers from the read values, so atoms cannot simply vanish

ag9xc · #3 Post by **ag9xc** » Wed Nov 19, 2008 4:26 pm

Dear admin,

yeah, I have done that. I have done these type of calculations before. I checked the POSCARS. I specified all the atoms for all the systems. Even I am surprised as to what is happening. Could you help me out. I appreciate your help.

Thanks,
Amit
<span class='smallblacktext'>[ Edited Wed Nov 19 2008, 05:29PM ]</span>