INSTRUCTIONS FOR DAY 3 (MASTANI, 2014), EXERCISE 3

Note that the following color code has been used in this instruction sheet:

Broad headings are in red.

File names are in magenta.

Phrases to be typed into the command line are in blue.

Input parameters are in dark green.

In this exercise, you will perform simple variable cell relax calculation for bulk Al.

• STEP 1: Go to the directory ~/hands_on/week1/day5/exercise3 

You will see the following files:

day3_exercise3_instructions.html this file!

Al.vc-relax.in this is a sample vc-relax input file, for bulk Al.

• STEP 2: Open and read the sample file Al.vc-relax.in

• We are considering the bulk Al. Notice we also need to calculate stress for this calculation. 
• Open the structure in xcrysden. 

• STEP 3: Run the vc-relax calculation:

• Run the scf calculation 

/usr/local/apps/espresso-5.1/bin/pw.x < Al.vc-relax.in > Al.vc-relax.out

• STEP 4: Read the output, and answer the following questions:

• Check the stress values. What do you notice? 
• Check the force values. What are the values? Do you understand why you get these values? 
• Compare the lattice constant which you get from this calculations with that from a series of scf calculations.