SCAN+rVV10

[caperott]

Hi, I am giving a try to SCAN+rVV10 using the master branch of QE available at https://github.com/QEF/q-e as of Sept. 24, 2017. QE was compiled against libxc (trunk, > 3.0.0) and rVV10 kernel table was generated by generate_rVV10_kernel_table.x and copied to the pseudo dir. As a test case I chose hexagonal boron nitride.

The issue I am facing with is that pw.x returns the same energies for input_dft = 'scan' and for input_dft = "scan+sla+pw+rw86+pbc+vv10" (i.e., for SCAN + rVV10). The code seems to identify correctly the string given to input_dft, e.g., for input_dft = 'scan' the output file gives "Exchange-correlation = SCAN ( 0 0 0 0 0 5)" and, for input_dft = "scan+sla+pw+rw86+pbc+vv10", the output files gives "Exchange-correlation = SCAN+SLA+PW+RW86+PBC+VV10 ( 1 4 13 4 3 5)". In both cases, however, I got exactly the same energies after SCF convergence,

 one-electron contribution =     -24.10068669 Ry
 hartree contribution      =      19.84906654 Ry
 xc contribution           =      -0.85528009 Ry
 ewald contribution        =     -32.41964182 Ry

Using the same input file with (only) rVV10 worked like a charm, giving the correct interplanar distance for hexagonal boron nitride. Furthermore, when running pw.x with input_dft = 'rVV10' (or "sla+pw+rw86+pbc+vv10") I got the following in the output file:

---

Carrying out rVV10 run using the following parameters: Nqs = 20 Nr_points = 1024 r_max = 100.000 b_value = 6.30000 beta = 0.00901 q_mesh = 0.00010000 0.00030000 0.00058939 0.00100810 0.00161396 0.00249058 0.00375900 0.00559430 0.00824984 0.01209221 0.01765183 0.02569619 0.03733578 0.05417739 0.07854596 0.11380545 0.16482331 0.23864234 0.34545298 0.50000000

Gradients computed in Reciprocal space

---

The above message does not appears in the output file when using input_dft = "scan+sla+pw+rw86+pbc+vv10".

It seems that rVV10 is not being used in calculations with input_dft = "scan+sla+pw+rw86+pbc+vv10"...

Here is the input file I used in these tests:

&CONTROL title = 'hBN' calculation = 'scf' restart_mode = 'from_scratch' outdir = './files' wfcdir = './files' pseudo_dir = "../pseudo" prefix = 'hbn' disk_io = 'default' verbosity = 'default' nstep = 400 /

&SYSTEM space_group = 194 a = 2.503374 c = 6.80 origin_choice = 1 nat = 2 ntyp = 2 ecutwfc = 120 ecutrho = 480 input_dft = "scan+sla+pw+rw86+pbc+vv10" /

&ELECTRONS electron_maxstep = 200 conv_thr = 1.0D-9 diago_thr_init = 1e-4 startingpot = 'atomic' startingwfc = 'atomic' mixing_mode = 'plain' mixing_beta = 0.5 mixing_ndim = 8 diagonalization = 'david' /

ATOMIC_SPECIES B 10.8110000000 B.pbe-hgh.UPF N 14.0067000000 N.pbe-hgh.UPF

ATOMIC_POSITIONS crystal_sg B 0.33333333333333 0.66666666666667 0.25000000000000 N 0.33333333333333 0.66666666666667 0.75000000000000

K_POINTS automatic 21 21 7 0 0 0

Regards, Claudio

[pchuy1906]

Hi Claudio, I have the same problem. How can you solve this problem? Thanks, Huy

[caperott]

Huy,

Unfortunately, I did not solve the problem. In fact, despite SCAN_rVV10 is available from libxc, the non-local correlation is not computed by libxc and, accordingly, using SCAN_rVV10 withing QE is not just a matter of including the libxc funcs_id associated to this xc functional.

Sorry...

Claudio

--

Cláudio A. Perottoni

Universidade de Caxias do Sul Rua Francisco Getúlio Vargas, 1130 95070-560 Caxias do Sul - RS - Brazil http://www.researcherid.com/rid/B-8409-2008

On Tue, Feb 27, 2018 at 11:01 PM, Huy Pham notifications@github.com wrote:

Hi Claudio, I have the same problem. How can you solve this problem? Thanks, Huy

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[pchuy1906]

I see. Thank you! Huy