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 -7.916460522208 -0.69 4.8 114ms
2 -7.921206943514 -2.32 -1.52 1.0 54.6ms
3 -7.921405754784 -3.70 -2.49 1.4 61.9ms
4 -7.921441086457 -4.45 -2.83 2.5 79.4ms
5 -7.921441639291 -6.26 -2.99 1.0 89.0ms
6 -7.921442009789 -6.43 -4.52 1.0 58.0ms
7 -7.921442021845 -7.92 -4.61 3.0 83.7ms
8 -7.921442022131 -9.54 -5.26 1.0 55.6ms
9 -7.921442022143 -10.92 -5.77 1.4 64.3ms
10 -7.921442022144 -11.99 -6.00 1.8 69.7ms
11 -7.921442022144 -12.37 -7.31 1.0 91.6ms
12 -7.921442022144 -13.65 -7.09 2.8 88.0ms
13 -7.921442022144 + -15.05 -7.65 1.0 61.2ms
14 -7.921442022144 -14.75 -9.19 1.1 112ms
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
---- ------- ------ ---------- ------- ------ ---------------
20.0 2.65s Non-interacting
1 0 1 0.31 14.8 13.3s
2 0 2 -0.52 13.1 1.23s
3 0 3 -2.40 11.7 1.12s
4 0 4 -4.46 8.6 872ms
5 0 5 -6.46 5.2 626ms
6 0 6 -8.92 1.0 359ms
7 1 1 -7.84 16.6 1.86s Restart
8 1 2 -8.98 2.1 408ms
18.7 2.22s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.51s Non-interacting
1 0 1 0.31 14.8 1.39s
2 0 2 -0.52 13.1 1.21s
3 0 3 -2.40 11.7 1.10s
4 0 4 -4.46 8.6 871ms
5 0 5 -6.46 5.2 647ms
6 0 6 -8.92 1.0 365ms
7 1 1 -7.84 16.6 1.69s Restart
8 1 2 -8.98 2.1 397ms
18.7 1.63s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.52s Non-interacting
1 0 1 0.31 14.8 1.41s
2 0 2 -0.52 13.1 1.20s
3 0 3 -2.40 11.7 1.10s
4 0 4 -4.46 8.6 901ms
5 0 5 -6.46 5.2 631ms
6 0 6 -8.92 1.0 439ms
7 1 1 -7.84 16.6 2.30s Restart
8 1 2 -8.98 2.1 370ms
18.7 1.62s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.44s Non-interacting
1 0 1 0.31 14.8 1.41s
2 0 2 -0.52 13.1 1.18s
3 0 3 -2.40 11.7 1.06s
4 0 4 -4.46 8.6 864ms
5 0 5 -6.46 5.2 628ms
6 0 6 -8.92 1.0 372ms
7 1 1 -7.84 16.6 1.64s Restart
8 1 2 -8.96 2.1 406ms
18.7 1.59s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.47s Non-interacting
1 0 1 0.31 14.8 1.47s
2 0 2 -0.52 13.1 1.24s
3 0 3 -2.40 11.7 1.13s
4 0 4 -4.46 8.6 884ms
5 0 5 -6.46 5.2 637ms
6 0 6 -8.92 1.0 341ms
7 1 1 -7.84 16.6 1.75s Restart
8 1 2 -8.96 2.1 394ms
18.7 1.66s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.57s Non-interacting
1 0 1 0.31 14.8 1.41s
2 0 2 -0.52 13.1 1.24s
3 0 3 -2.40 11.7 1.11s
4 0 4 -4.46 8.6 879ms
5 0 5 -6.46 5.2 634ms
6 0 6 -8.92 1.0 368ms
7 1 1 -7.84 16.6 1.70s Restart
8 1 2 -8.96 2.1 454ms
18.7 2.33s Final orbitals
108.236910 seconds (137.41 M allocations: 23.483 GiB, 3.95% gc time, 31.98% compilation time)
These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.0034981553583671807
-0.0029774511595321365
-0.0029774511595236433
0.004302230630494961
0.004302230630659632
0.004353201760104519