qeijo 0.1

Lightweight library to easily launch ab initio calculations with Quantum Espresso.

First of all, qeijo is not an acronym. Okay, we have the Q and E for Quantum Espresso, for sure, but that's it. The point was just to use a funny name for the package.

qeijo is an incorrect way - on purpose, of course - of spelling "queijo", which is simply the Portuguese word for "cheese".

This package contains a lightweight library that allows the user to launch electronic structure calculations with Quantum Espresso and then collect the results, all done in a Pythonic way. Just to be clear, I don't claim that this package can compete in terms of features with much larger frameworks for atomistic simulations, like ASE. All you can expect from qeijo is that it is light and easy to use.

In version 0.1, there is only one module, pw, which must be used to build an input to the pw.x program, launch a total energy calculation and get from it important quantities, like the total energy of the system, the relaxed atomic coordinates, magnetization, etc. In future releases, I plan to add interfaces to other programs from the Quantum Espresso package, as well as work a bit more on user documentation.

Basic Usage Example

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# Launching a calculation with pw.x of H2 molecule, reading the input from an existing input file
from qeijo import pw

cmd="mpirun -np 2 pw.x"
h2_calc=pw.calc()
h2_calc.read_input("h2.inp")
inpstr=h2_calc.build_input()
h2_out=h2_calc.run(command_line=cmd,input_string=inpstr,saveout=True,
                   outfile="h2.out",savecoords=True,coordfile="h2.xyz")

# Print the total energy in eV
print("Total energy: %f" % h2_out.energy[-1])

# Print the relaxed coordinates of the the two H atoms
print("H1: %f %f %f" % (h2_out.x[0],h2_out.y[0],h2_out.z[0]))
print("H2: %f %f %f" % (h2_out.x[1],h2_out.y[1],h2_out.z[1]))