day3

Day 3 tutorials



Tutorial 7: 2D systems: monolayers, slabs and surfaces

https://drive.google.com/open?id=11wHw1iQpsWCHHqQd3wPNL_5d_T_wBEQO


Tutorial 8: "a "constrain method" in EA: looking for metastable"

https://drive.google.com/open?id=1-9_nJepxFPbUGTSyR8DiU3dMrdj-NWf6


Tutorial 7: Predicting 2D materials

@Rennes 1 University

Busheng Wang, Heng Zhang & Gilles Frapper

IC2MP, Poitiers University - CNRS

OUTLINE

- Fixed-composition Prediction, -200, EX07-2D_Si

- Variable-composition Prediction, -201, EX31_2D_varcomp_SnS

- Parameters in INPUT.txt for 2D monolayer/slab

-Surface (EX23_MgO_surface)

7.1 Log in your account

ssh –oPort=86 uspexXX@thor.univ-poitiers.fr

LOGIN: uspexXX (with XX=10-32)

PWD: ?Ic2Mp;UsPeX!

Copy USPEX_Manualif you need.

cp -r /home/gfrapper/USPEX_workshop/USPEX_Manual_English.pdf .

7.2 EX07-2D_Si VASP

Copy Example07

cp -R /home/gfrapper/USPEX_workshop/Day3/EX07-2D_Si .

Edit INPUT.txt

vi INPUT.txt

One error:

% vacuumSize

8 9 10 12

% EndVacuumSize

% vacuumSize

20 20 20 20 20

% EndVacuumSize

Default: 10 Å for every step of relaxation

Note:

(1) vacuumSize in 2D structure prediction is the lattice parametercof 2D crystal along z direction, which is different from the vacuumSize in surface structure prediction(200, 201)

Edit the Queue information.

R1067861 (500 cores) for uspex01~20; R1068123 (300 cores) for uspex20-40).

vi runuspex.sh

vi Submission/submitJob_local.py

vi Submission/checkStatus_local.py

output = unicode(check_output(u'/sw/pbs/default/bin/qstat -u {}'.format('userXX') , shell=True))

# In calculation node of Thor, 'qstat jobID' jobID will be followed with '.service0' automatically, error. But 'qstat -u username' works well.

Submit job

qsub runuspex.sh

Check results

vi reference/OUTPUT.txt

vi reference/BESTIndividuals

vi reference/BESTIndividuals_POSCARS

vi reference/goodStructures

vi reference/goodStructures_POSCARS

Or

Download the reference file from Thor to local machines, then use GDIS to have a look.

scp -oPort=86 -r uspexXX@thor.univ-poitiers.fr:/directory/reference .

Password (?Ic2Mp;UsPeX!)

Note:

(1) Prediction of 2D AmBnby formula is available.

% atomType

A B

% EndAtomType

% numSpecies

m n

% EndNumSpecies

6: minAt

12: maxAt


7.3 EX31_2D_varcomp_SnS VASP

cp -R /home/gfrapper/USPEX_workshop/Day3/EX31_2D_varcomp_SnS .

vi INPUT.txt

vi reference/OUTPUT.txt

vi reference/extended_convex_hull

vi reference/extended_convex_hull_POSCARS

Open reference/extendedConvexHull.pdf in Windows

Note:

(1) Because we have confined the thickness for 2D structures, we will discard the structures with thickness after relaxation greater than thicknessS+3Å.

(2) For -201 prediction, the convex hullis calculated with respect to the energy of 2D elemental materials.

7.4 Necessary parameters in INPUT.txt (USPEX_Manual-10.2, Page 54, 75-77)

calculationType, symmetries, vacuumSize, atomType, numSpecies, minAt, maxAt

-200/-201/-s200/-s201 : calculationType

% symmetries

2-80

% endSymmetries

3.0 : thicknessS

% vacuumSize

20 20 20 20 20

% EndVacuumSize

% atomType

Si O

% EndAtomType

-200: fixed-composition prediction

-201: variable-composition prediction

% numSpecies

1 2

% EndNumSpecies

% numSpecies

1 2

% EndNumSpecies

3: minAt

9: maxAt

% numSpecies

1 0

0 1

% EndNumSpecies

4 : minAt

20 : maxAt

Note:

(1) Magnetic calculation (-s200, -s201) is only supported in VASP.


TUTORIAL Surface (EX23_MgO_surface)

1. To perform a prediction of surface reconstructions, you have to:

• Specify 200 or 201 : calculationType.

Provide a file containing substratein VASP5 POSCAR format.

5.0 : thicknessS (thickness of surface region)

3.0 : thicknessB (thickness of buffer region)

4 : reconstruct (maximum multiplications of cell)

% symmetries

2-17

% endSymmetries

% vacuumSize

10 10 15 20

% EndVacuumSize


Specify the following parameters:

Fig. 1 The surface model used in USPEX.


2. Create new folder and cd into it:

> mkdir Day3/EX23&& cd Day3/EX23

3. Copy the files for example 23:

> cp -r /home/gfrapper/USPEX_workshop/Day3/EX23_MgO_surface/* .

(Here everything is set up for submission on thor)

4. Run the calculation:

> qsub runuspex.sh

5. Download the results folder to your local machine,using the GDIS code:

(Under the local machine copy the results directory to local_dir)

> mkdirlocal_dircd local_dir

> scp -r -oPort=86 uspexXX@@thor.univ-poitiers.fr:path_to_results_dir .

> gdis results1/OUTPUT.txt