Dear all, In one of my projects I would need to compute the Gibbs free energies of structures along a reaction path. After looking through the QE webpage, the pw_forum, and the documentation in the quantum espresso installation directory I think I understand the general procedure:
1. one calculates the phonons 2. one computes the interatomic Force Constants with the q2r.x program 3. one uses the matdyn.x to produce input for the F_QHA.x program 4. with the F_QHA.x program one can compute the Gibbs free energy and other thermodynamical properties. (please correct me if I have misunderstood this general procedure) The problem is that I have so far only managed to complete step 1, to compute the phonons. I am currently doing test calculations on a water molecule and this is the input file of the phonon calculation: phonons of H2O in super cell at Gamma &inputph outdir='./', prefix='h2o', amass(1)=1.01, amass(2)=16.01, fildyn='h2o.dynG', trans= .true. / 0.0 0.0 0.0 I then try to run the q2r.x calculation with the following input: test of q2r calculation &input fildyn='h2o.dynG', flfrc='h2o-output-q2r.fc', zasr='no' This calculation crashes presumably because it expects a file called h2o.dynG0. But from where do I get this file? As far as I can see the phonon calculation only produces the file h2o.dynG, not a h2o.dynG0 file. I am completely lost at the moment so I would appreciate if anyone could help me with carrying out the q2r calculation correctly. Thank you very much in advance, Yours sincerely, Torstein Fjermestad, University of Oslo, Norway
