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);
nothing # hiden Energy log10(ΔE) log10(Δρ) Diag Δtime
--- --------------- --------- --------- ---- ------
1 -7.916462411600 -0.69 4.9 109ms
2 -7.921203989672 -2.32 -1.52 1.0 55.2ms
3 -7.921403882676 -3.70 -2.49 1.4 59.1ms
4 -7.921441018267 -4.43 -2.82 2.5 78.2ms
5 -7.921441605597 -6.23 -2.98 1.2 60.0ms
6 -7.921442007078 -6.40 -4.45 1.0 56.4ms
7 -7.921442021788 -7.83 -4.58 2.9 86.4ms
8 -7.921442022125 -9.47 -5.15 1.0 55.6ms
9 -7.921442022139 -10.83 -5.41 1.1 56.8ms
10 -7.921442022143 -11.42 -5.82 1.4 59.9ms
11 -7.921442022144 -12.00 -7.22 1.1 58.0ms
12 -7.921442022144 -13.15 -7.12 2.9 167ms
13 -7.921442022144 -14.45 -7.51 1.0 60.5ms
14 -7.921442022144 + -14.75 -8.13 1.0 59.7ms
Next 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]);
nothing # hideIter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 2.07s Non-interacting
1 0 1 0.31 52.5 9.15s
2 0 2 -0.52 46.9 1.39s
3 0 3 -2.40 41.7 1.25s
4 0 4 -4.46 29.6 988ms
5 0 5 -6.46 17.3 719ms
6 0 6 -8.91 4.0 429ms
7 1 1 -7.86 55.5 2.02s Restart
8 1 2 -8.91 5.6 485ms
72.7 2.63s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.61s Non-interacting
1 0 1 0.31 52.5 1.60s
2 0 2 -0.52 46.9 1.37s
3 0 3 -2.40 41.7 1.26s
4 0 4 -4.46 29.6 984ms
5 0 5 -6.46 17.3 717ms
6 0 6 -8.91 4.0 440ms
7 1 1 -7.86 55.5 1.90s Restart
8 1 2 -8.91 5.6 463ms
72.8 1.81s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.65s Non-interacting
1 0 1 0.31 52.5 1.57s
2 0 2 -0.52 46.9 1.36s
3 0 3 -2.40 41.7 1.26s
4 0 4 -4.46 29.6 978ms
5 0 5 -6.46 17.3 1.58s
6 0 6 -8.91 4.0 404ms
7 1 1 -7.86 55.5 1.79s Restart
8 1 2 -8.91 5.6 465ms
72.8 1.80s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.66s Non-interacting
1 0 1 0.31 52.5 1.60s
2 0 2 -0.52 46.9 1.37s
3 0 3 -2.40 41.7 1.28s
4 0 4 -4.46 29.6 984ms
5 0 5 -6.46 17.3 742ms
6 0 6 -8.91 4.0 428ms
7 1 1 -7.86 55.5 1.88s Restart
8 1 2 -8.91 5.6 457ms
72.8 1.79s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.64s Non-interacting
1 0 1 0.31 52.5 2.38s
2 0 2 -0.52 46.9 1.29s
3 0 3 -2.40 41.7 1.25s
4 0 4 -4.46 29.6 975ms
5 0 5 -6.46 17.3 723ms
6 0 6 -8.91 4.0 431ms
7 1 1 -7.86 55.5 1.88s Restart
8 1 2 -8.91 5.6 467ms
72.8 1.81s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.65s Non-interacting
1 0 1 0.31 52.5 1.58s
2 0 2 -0.52 46.9 1.36s
3 0 3 -2.40 41.7 1.24s
4 0 4 -4.46 29.6 964ms
5 0 5 -6.46 17.3 714ms
6 0 6 -8.91 4.0 426ms
7 1 1 -7.86 55.5 2.72s Restart
8 1 2 -8.91 5.6 429ms
72.8 1.69s Final orbitals
112.442069 seconds (151.08 M allocations: 82.616 GiB, 8.47% gc time, 26.18% compilation time)
These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.003498155352349171
-0.0029774511551668627
-0.002977451155069899
0.0043022306431483755
0.00430223064323123
0.004353201771464269