Phonon computations
This is a quick sketch how to run a simple phonon calculation using DFTK.
Practical phonon computations have only seen rudimentary testing as of now. As of now we do not yet recommend relying on this feature for production calculations. We appreciate any issues, bug reports or PRs.
First we run an SCF calculation.
using AtomsBuilder
using DFTK
using PseudoPotentialData
pseudopotentials = PseudoFamily("cp2k.nc.sr.lda.v0_1.semicore.gth")
model = model_DFT(bulk(:Si); pseudopotentials, functionals=LDA())
basis = PlaneWaveBasis(model; Ecut=10, kgrid=[4, 4, 4])
scfres = self_consistent_field(basis, tol=1e-8);n Energy log10(ΔE) log10(Δρ) Diag Δtime
--- --------------- --------- --------- ---- ------
1 -7.916260211081 -0.69 4.8 107ms
2 -7.921122918413 -2.31 -1.52 1.0 54.5ms
3 -7.921409201159 -3.54 -2.49 1.9 63.3ms
4 -7.921441115502 -4.50 -2.90 2.4 73.1ms
5 -7.921441828390 -6.15 -3.23 1.2 56.6ms
6 -7.921442010698 -6.74 -4.49 1.1 56.0ms
7 -7.921442022080 -7.94 -5.08 2.9 81.9ms
8 -7.921442022142 -10.21 -5.51 1.6 61.9ms
9 -7.921442022143 -12.09 -5.45 1.4 58.6ms
10 -7.921442022144 -11.91 -6.42 1.0 55.0ms
11 -7.921442022144 -13.17 -7.85 1.6 62.1ms
12 -7.921442022144 -14.27 -8.40 3.1 85.2msNext we compute the phonon modes at the q-point [1/4, 1/4, 1/4].
scfres = DFTK.unfold_bz(scfres)
phret_q0 = @time DFTK.phonon_modes(scfres; q=[0.25, 0.25, 0.25]);Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 2.07s Non-interacting
1 0 1 0.31 52.5 3.79s
2 0 2 -0.52 47.0 1.32s
3 0 3 -2.40 41.8 1.21s
4 0 4 -4.46 29.7 942ms
5 0 5 -6.46 17.4 679ms
6 0 6 -8.91 4.0 417ms
7 1 1 -7.87 55.4 1.86s Restart
8 1 2 -9.14 5.6 453ms
72.8 1.75s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.59s Non-interacting
1 0 1 0.31 52.5 1.51s
2 0 2 -0.52 47.0 1.37s
3 0 3 -2.40 41.8 1.21s
4 0 4 -4.46 29.7 935ms
5 0 5 -6.46 17.4 686ms
6 0 6 -8.91 4.0 412ms
7 1 1 -7.87 55.4 1.82s Restart
8 1 2 -9.14 5.6 440ms
72.8 1.79s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.62s Non-interacting
1 0 1 0.31 52.5 1.53s
2 0 2 -0.52 47.0 1.32s
3 0 3 -2.40 41.8 1.20s
4 0 4 -4.46 29.7 933ms
5 0 5 -6.46 17.4 680ms
6 0 6 -8.91 4.0 413ms
7 1 1 -7.87 55.4 1.80s Restart
8 1 2 -9.14 5.6 457ms
72.8 1.75s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.60s Non-interacting
1 0 1 0.31 52.5 1.50s
2 0 2 -0.52 47.0 2.77s
3 0 3 -2.40 41.8 1.37s
4 0 4 -4.46 29.7 897ms
5 0 5 -6.46 17.4 687ms
6 0 6 -8.91 4.0 413ms
7 1 1 -7.86 55.4 1.81s Restart
8 1 2 -9.09 5.6 438ms
72.8 1.77s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.60s Non-interacting
1 0 1 0.31 52.5 1.54s
2 0 2 -0.52 47.0 1.31s
3 0 3 -2.40 41.8 1.20s
4 0 4 -4.46 29.7 957ms
5 0 5 -6.46 17.4 692ms
6 0 6 -8.91 4.0 418ms
7 1 1 -7.86 55.4 1.83s Restart
8 1 2 -9.09 5.6 447ms
72.8 1.76s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.62s Non-interacting
1 0 1 0.31 52.5 1.48s
2 0 2 -0.52 47.0 1.29s
3 0 3 -2.40 41.8 1.17s
4 0 4 -4.46 29.7 933ms
5 0 5 -6.46 17.4 674ms
6 0 6 -8.91 4.0 406ms
7 1 1 -7.86 55.4 1.77s Restart
8 1 2 -9.09 5.6 440ms
72.9 1.74s Final orbitals
85.674790 seconds (101.37 M allocations: 80.356 GiB, 7.96% gc time, 8.68% compilation time: 100% of which was recompilation)These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.003498155353756112
-0.0029774511554444545
-0.00297745115520175
0.004302230637420741
0.00430223063744881
0.004353201766838269