About phonon calculations,

[cwandtj]

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

[alex]

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

[cwandtj]

Thank you for your reply, Alex.

I will try as you suggested.

CW