VASP Computing Bulk Modulus of Au - Revision history

Yanmingw at 09:15, 4 September 2015

2015-09-04T09:15:44Z

← Older revision		Revision as of 09:15, 4 September 2015
Line 168:		Line 168:
	fit_a0B ('platt.B.dat');		fit_a0B ('platt.B.dat');

	The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. For simulation with US-LDA PP, the result is a0 = 4.068 ~~angstrom~~, Ecoh = -4.39 eV, B = 186 GPa.		The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. For simulation with US-LDA PP, the result is a0 = 4.068 <math>\AA</math>, Ecoh = -4.39 eV, B = 186 GPa.

Yanmingw at 09:12, 4 September 2015

2015-09-04T09:12:34Z

← Older revision		Revision as of 09:12, 4 September 2015
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	4.071 1 -.17546441E+02 -.17546412E+02 -.175464E+02		4.071 1 -.17546441E+02 -.17546412E+02 -.175464E+02
	4.072 1 -.17546288E+02 -.17546257E+02 -.175463E+02		4.072 1 -.17546288E+02 -.17546257E+02 -.175463E+02
	<\pre>		</pre>

	<tt>platt.B.dat</tt>		<tt>platt.B.dat</tt>
Line 161:		Line 161:
	4.071 -4.29 -4.29 -4.29		4.071 -4.29 -4.29 -4.29
	4.072 -5.63 -5.64 -5.64		4.072 -5.63 -5.64 -5.64
	<\pre>		</pre>

	Launch <tt>Matlab</tt> and run the following functions [[media:fit_a0EB.m.txt \| fit_a0EB.m]] and [[media:fit_a0B.m.txt \| fit_a0B.m]],		Launch <tt>Matlab</tt> and run the following functions [[media:fit_a0EB.m.txt \| fit_a0EB.m]] and [[media:fit_a0B.m.txt \| fit_a0B.m]],
Line 167:		Line 167:
	[a0, Ecoh, B] = fit_a0EB('Elatt.B.dat',4,4);		[a0, Ecoh, B] = fit_a0EB('Elatt.B.dat',4,4);
	fit_a0B ('platt.B.dat');		fit_a0B ('platt.B.dat');


	The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. For simulation with US-LDA PP, the result is a0 = 4.068 angstrom, Ecoh = -4.39 eV, B = 186 GPa.		The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. For simulation with US-LDA PP, the result is a0 = 4.068 angstrom, Ecoh = -4.39 eV, B = 186 GPa.

Yanmingw at 09:11, 4 September 2015

2015-09-04T09:11:55Z

← Older revision		Revision as of 09:11, 4 September 2015
Line 168:		Line 168:
	fit_a0B ('platt.B.dat');		fit_a0B ('platt.B.dat');

⚫	The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. In ~~this~~ ~~example~~, the result is a0 = 4.068 angstrom, Ecoh = -4.39 eV, B = 186 GPa.

		⚫	The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus. The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus. For simulation with US-LDA PP, the result is a0 = 4.068 angstrom, Ecoh = -4.39 eV, B = 186 GPa.
	===Parallel computation===

	To run <tt>vasp</tt> in parallel, you need to submit [[media:vasp.pbs.txt \| vasp.pbs]] as

	qsub vasp.pbs


	You will need the following two files to do this calculation in parallel on SU-AHPCRC:
	[[media:auto.B.par.Au.txt \| auto.B.par]] and
	[[media:B.pbs.Au.txt \| B.pbs]].

Yanmingw: /* Analyze data */

2015-09-04T09:11:06Z

Analyze data

@@ Line 134: / Line 134: @@
 ===Analyze data===
-After running it as <tt>./auto.B.serial</tt>, it will create data files <tt>Elatt.B.dat</tt> and <tt>platt.B.dat</tt>.
+After the simulation is finished, it will create data files <tt>Elatt.B.dat</tt> and <tt>platt.B.dat</tt>.
- fit_a0EB('Elatt.B.dat');
+<tt>platt.B.dat</tt>
  fit_a0B ('platt.B.dat');
-The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus.  The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus.  In this example, the result is a0 = 4.06 angstrom, Ecoh = -4.39 eV, B = 190 GPa.
+The first line fits the energy data to a quadratic curve and computes the equilibrium lattice constant, cohesive energy and bulk modulus.  The second line fits the pressure data to a linear curve and computes the equilibrium lattice constant and bulk modulus.  In this example, the result is a0 = 4.068 angstrom, Ecoh = -4.39 eV, B = 186 GPa.
 ===Parallel computation===

Yanmingw: /* Run VASP */

2015-09-04T09:06:27Z

Run VASP

← Older revision		Revision as of 09:06, 4 September 2015
Line 128:		Line 128:
	done		done
	</pre>		</pre>

			To submit the job, make sure '''POTCAR''', '''INCAR''' and '''KPOINTS''' are placed in the same folder of your '''PBS''' script, and then type the following command.
			qsub vasp.pbs

	===Analyze data===		===Analyze data===

Yanmingw: /* Run VASP */

2015-09-04T09:04:23Z

Run VASP

← Older revision		Revision as of 09:04, 4 September 2015
Line 64:		Line 64:
	===Run VASP===		===Run VASP===

			We can write one .pbs script to submit the VASP simulation request to the cluster.
	Now we are ready to run

		⚫	Using MC2 cluster as an example, we provide the following <tt>vasp.pbs</tt> for the calculation of equilibrium lattice constant, cohesive energy and bulk modulus of Au. The goal of this script is to run <tt>vasp</tt> in iterations with different lattice constants.
	vasp

⚫	To ~~compute~~ the equilibrium lattice constant, cohesive energy and bulk modulus, we ~~use~~ ~~the~~ ~~following~~ script ~~<tt>auto.B.serial</tt>~~ to run <tt>vasp</tt> ~~repeated~~ with different lattice constants.

	<pre>		<pre>

Yanmingw: /* Run VASP */

2015-09-04T09:03:08Z

Run VASP

@@ Line 72: / Line 72: @@
 <pre>
 #!/bin/bash
 do
 cat > POSCAR << FIN
 POSCAR for FCC Au (created manually)
    $a
-0.5  0.5
+.0  0    0
-.5  0    0.5
+1.0  0
-.5  0.5  0
+0    1.0
-Cartesian  (real coordinates r)
+direct  (real coordinates r)
-0    0
+0    0    T T T
 FIN
-echo "a=$a"
+echo "a=$a  ncpu=$ncpu"
 E=`tail -1 OSZICAR`
@@ Line 97: / Line 130: @@
 done
 </pre>
 ===Analyze data===

Yanmingw at 08:35, 4 September 2015

2015-09-04T08:35:34Z

← Older revision		Revision as of 08:35, 4 September 2015
Line 3:		Line 3:
	VASP: Computing Bulk Modulus of Au</STRONG></font></P>		VASP: Computing Bulk Modulus of Au</STRONG></font></P>
	<DIV>		<DIV>
	<P ALIGN="CENTER"><STRONG> </STRONG></P>		<P ALIGN="CENTER"><STRONG>Modified by Yanming Wang (Sep, 2015) </STRONG></P>
	</DIV>		</DIV>

Yanmingw: /* Input files */

2015-09-04T08:34:19Z

Input files

← Older revision		Revision as of 08:34, 4 September 2015
Line 59:		Line 59:
	</pre>		</pre>

			'''POTCAR'''
	To do this calculation, you also need to put the LDA pseudopotential file as <tt>POTCAR</tt> in this directory.
			A POTCAR file that specifies the pseudopotential is required to be in the same directory. In this example, we will present the results from two calculations with US-LDA PP and PAW-LDA PP.

	===Run VASP===		===Run VASP===

Yanmingw: /* Input files */

2015-09-04T08:31:07Z

Input files

← Older revision		Revision as of 08:31, 4 September 2015
Line 47:		Line 47:
	POSCAR for FCC Au (created manually)		POSCAR for FCC Au (created manually)
	4.068		4.068
	1.0 0 0		1.0 0 0
	0 1.0 0		0 1.0 0
	0 0 1.0		0 0 1.0
	4		4
	selective dynamics		selective dynamics
	direct (real coordinates r)		direct (real coordinates r)
	0 0 0 T T T		0 0 0 T T T
	0.5000 0.5000 0 T T T		0.5000 0.5000 0 T T T
	0 0.5000 0.5000 T T T		0 0.5000 0.5000 T T T
	0.5000 0 0.5000 T T T		0.5000 0 0.5000 T T T
	</pre>		</pre>