Hi folks,
Kind of new to Vasp. My question is likely to be naive!
I am trying to adsorb a molecule on top of a Rh surface. Vasp complains distances are small and of course crashes.
Two questions:
[1] What software (free preferably) is good enough to build my system.
[2] Is it possible for someone to share with me a correct input file Molecule + Surface (Any molecule, any surface will do!).
Thanks all
Ahmed
Adsorption of a molecule on a surface
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ahmed2004
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Adsorption of a molecule on a surface
Last edited by ahmed2004 on Wed May 07, 2008 7:29 pm, edited 1 time in total.
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admin
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Adsorption of a molecule on a surface
please check:
--) did this error occur in the first ionic step? If so, there is an error in the POSCAR file (you can have a short look to the OUTCAR file to find out which atoms are too close)
--) if the error occured in a subsequent run (starting from a pre-converged geometry as read from CONTCAR) , the ionic optimization of VASP has lead to an unreasonable geometry. In this case, please check:
a) are all previous ionic steps converged electronically (EDIFF convergence criterium is matched) or did they finish after the default number of 60 el steps. If EDIFF is not reached, the calculated forces are certainly unreasonable. ---> please increase NELM in INCAR
b) did the ionic relaxation algorithm itself lead to an unreasonable geometry, although each step was converged electronically? If so, please change the relaxation algorithm (IBRION) and reduce the step width of the relaxation steps (POTIM, default=0.5)
--) did this error occur in the first ionic step? If so, there is an error in the POSCAR file (you can have a short look to the OUTCAR file to find out which atoms are too close)
--) if the error occured in a subsequent run (starting from a pre-converged geometry as read from CONTCAR) , the ionic optimization of VASP has lead to an unreasonable geometry. In this case, please check:
a) are all previous ionic steps converged electronically (EDIFF convergence criterium is matched) or did they finish after the default number of 60 el steps. If EDIFF is not reached, the calculated forces are certainly unreasonable. ---> please increase NELM in INCAR
b) did the ionic relaxation algorithm itself lead to an unreasonable geometry, although each step was converged electronically? If so, please change the relaxation algorithm (IBRION) and reduce the step width of the relaxation steps (POTIM, default=0.5)
Last edited by admin on Thu May 08, 2008 12:35 pm, edited 1 time in total.