# Crystalline silicon : computation of the total energy # #Definition of the unit cell acell 3*10.18 # This is equivalent to 10.18 10.18 10.18 rprim 0.0 0.5 0.5 # In tutorials 1 and 2, these primitive vectors 0.5 0.0 0.5 # (to be scaled by acell) were 1 0 0 0 1 0 0 0 1 0.5 0.5 0.0 # that is, the default. #Definition of the atom types ntypat 1 # There is only one type of atom znucl 14 # The keyword "znucl" refers to the atomic number of the # possible type(s) of atom. The pseudopotential(s) # mentioned in the "files" file must correspond # to the type(s) of atom. Here, the only type is Silicon. pp_dirpath "$ABI_PSPDIR" # This is the path to the directory were # pseudopotentials for tests are stored pseudos "Pseudodojo_nc_sr_04_pw_standard_psp8/Si.psp8" # Name and location of the pseudopotential #Definition of the atoms natom 2 # There are two atoms typat 1 1 # They both are of type 1, that is, Silicon. xred # This keyword indicate that the location of the atoms # will follow, one triplet of number for each atom 0.0 0.0 0.0 # Triplet giving the REDUCED coordinate of atom 1. 1/4 1/4 1/4 # Triplet giving the REDUCED coordinate of atom 2. # Note the use of fractions (remember the limited # interpreter capabilities of ABINIT) #Definition of the planewave basis set ecut 12.0 # Maximal kinetic energy cut-off, in Hartree #Definition of the k-point grid kptopt 1 # Option for the automatic generation of k points, taking # into account the symmetry ngkpt 2 2 2 # This is a 2x2x2 grid based on the primitive vectors nshiftk 4 # of the reciprocal space (that form a BCC lattice !), # repeated four times, with different shifts : shiftk 0.5 0.5 0.5 0.5 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.5 # In cartesian coordinates, this grid is simple cubic, and # actually corresponds to the # so-called 4x4x4 Monkhorst-Pack grid #Definition of the SCF procedure nstep 10 # Maximal number of SCF cycles toldfe 1.0d-6 # Will stop when, twice in a row, the difference # between two consecutive evaluations of total energy # differ by less than toldfe (in Hartree) # This value is way too large for most realistic studies of materials diemac 12.0 # Although this is not mandatory, it is worth to # precondition the SCF cycle. The model dielectric # function used as the standard preconditioner # is described in the "dielng" input variable section. # Here, we follow the prescription for bulk silicon. ############################################################## # This section is used only for regression testing of ABINIT # ############################################################## #%% #%% [setup] #%% executable = abinit #%% [files] #%% files_to_test = #%% tbase3_1.abo, tolnlines= 0, tolabs= 0.000e+00, tolrel= 0.000e+00 #%% [paral_info] #%% max_nprocs = 4 #%% [extra_info] #%% authors = Unknown #%% keywords = #%% description = Crystalline silicon: computation of the total energy #%%