At present, I am a little confused about the setting of the q vector in the phonon calculation process.
According to the abinit official website tutorial (https://docs.abinit.org/tutorial/rf2/) and workshop resources (http://palata.fzu.cz/abinitschool/download/Tu2_calc_phonons.pdf), there are two different q vector setting methods. For examples:
Method 1: from https://docs.abinit.org/tutorial/rf2/
#Q vectors for all datasets #Complete set of symmetry-inequivalent qpt chosen to be commensurate # with kpt mesh so that only one set of GS wave functions is needed. #Generated automatically by running GS calculation with kptopt=1, # nshift=0, shiftk=0 0 0 (to include gamma) and taking output kpt set # file as qpt set. Set nstep=1 so only one iteration runs. nqpt 1 # One qpt for each dataset (only 0 or 1 allowed) # This is the default for all datasets and must # be explicitly turned off for dataset 1. qpt2 0.00000000E+00 0.00000000E+00 0.00000000E+00 qpt3 0.00000000E+00 0.00000000E+00 0.00000000E+00 qpt4 2.50000000E-01 0.00000000E+00 0.00000000E+00 qpt5 5.00000000E-01 0.00000000E+00 0.00000000E+00 qpt6 2.50000000E-01 2.50000000E-01 0.00000000E+00 qpt7 5.00000000E-01 2.50000000E-01 0.00000000E+00 qpt8 -2.50000000E-01 2.50000000E-01 0.00000000E+00 qpt9 5.00000000E-01 5.00000000E-01 0.00000000E+00 qpt10 -2.50000000E-01 5.00000000E-01 2.50000000E-01
nqpt 1 iqpt: 0 iqpt+ 1
Compared to Method 1, Method 2 is more convenient. Because method 1 needs to manually set the q vector.
I want to know if Method 2 is currently available in version Abinit 9.2.2 version and how to determine the value of ndtset.
See the attachment for the complete input file of the two methods.