How to calculate the single point energy?

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lanjh · #1 Post by **lanjh** » Tue Jan 09, 2007 12:31 pm

hi, everyone~
I have a question about vasp. I want to calculate the single energy at each distance between the adsorption species and the slab, can anyone tell me how to do that?

#2 Post by **admin** » Wed Jan 10, 2007 4:09 pm

you can do this either
1) on the job-script level (i.e. preparing different POSCARs and running vasp in a do-loop with IBRION=-1;NSW=0, saving the totla energies of each step)
or
2) in a 'constant velocity' MD run setting
IBRION=0; SMASS=-2; POTIM=1
and assigning all velocities but the approaching adsorbate's one to 0.0 0.0 0.0 in POSCAR
please have a look into the online handbook, chapter Examples: Dimers for that setup.

lanjh · #3 Post by **lanjh** » Mon Jan 15, 2007 7:11 am

thank you for your reply. But I still have a problem. How to set the key If I want to optimize the system during each distance?

tjf · #4 Post by **tjf** » Mon Jan 15, 2007 11:13 am

Look up selective dynamics in the manual. You'll need to fix (say) z coordinates of an adsorbate atom and a couple of surface atoms.