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Dear all,

I am trying to do frequency calculations on bulk and adsorbate on surface. My questions are:

1) I use IBRION=5 and got following information.

60 f/i= 0.047549 THz 0.298759 2PiTHz 1.586064 cm-1 0.196647 meV
X Y Z dx dy dz
3.077752 1.971981 5.505232 -0.031751 0.004353 0.003008
5.414283 5.915942 2.727125 -0.031776 0.004379 0.002445
2.583605 5.915942 0.050983 -0.031814 0.004351 0.003020
0.247073 1.971981 2.829090 -0.031723 0.004376 0.002433
0.000000 0.000000 0.000000 -0.031900 0.004322 0.002458
0.000000 3.943961 0.000000 -0.031966 0.004460 0.002450
2.830678 0.000000 2.778107 -0.031879 0.004325 0.002920
2.830678 3.943961 2.778107 -0.031922 0.004446 0.002958
4.480415 0.341963 3.944346 -0.031125 0.004232 0.002468
4.011620 7.545960 1.166239 -0.031208 0.004321 0.002656
1.180942 4.285924 1.611868 -0.031285 0.004396 0.002590
1.649737 3.601999 4.389975 -0.031228 0.004327 0.002698
1.180942 7.545960 1.611868 -0.031173 0.004231 0.002499
1.649737 0.341963 4.389975 -0.031168 0.004305 0.002700
4.480415 3.601999 3.944346 -0.031210 0.004396 0.002533
4.011620 4.285924 1.166239 -0.031288 0.004302 0.002639
5.541275 1.971981 0.452535 -0.030986 0.004348 0.002414
2.950760 5.915942 3.230643 -0.031013 0.004354 0.002817
0.120081 5.915942 5.103679 -0.031001 0.004355 0.002432
2.710597 1.971981 2.325572 -0.030998 0.004359 0.002829

Is there any way to get partial phonon DOS for each component?

2) In frequecy calculations of adsorbate (O2) on surface, I wonder how we can say frequency of bend and stretch modes and how we can extract such info from IBRION=5 calculations?

3) For 2), can you estimate no. of layers must be relaxed from surface? two layers from top? or you can only allow adsorbate to relax?

Thank you,

CW

1) no idea
2) p4vasp should do the job (visualization)
3) start with O2 only, then with plus 1 layer and so on. Check convergence of the wavenumbers you are interested in afterwards.

Cheers

alex

Thank you for your reply, Alex.

I will try as you suggested.

CW