Hi,

Sorry first for a trivial question! I wonder if there is a general rule to how to run a calculation using hybrid functionals with cutting off the long range coulomb interactions. I noticed there is a tag “fock_icutcoul” and as it is mentioned the “OPTION 5” (ERFC for short range interaction) is hard-coded for hybrids. In that case do I need to set the “rcut” value (e.g. HSE06)?

The main idea is calculating the formation energies for the defects using hybrid functional and I also need to optimize the cell and geometry. Here is a part of the input file:

ndtset 1

jdtset 3

paral_kgb 1

enunit 1

#iomode 3

#####################################################################################

# A SCF calculation

prtden1 1 # Print the density, for use by dataset 2

tolvrs1 1.0d-18 # This value is way too large for most realistic studies of materials

##prtdos1 3

#########################

# Non- SCF for wavefunctions

```
iscf2 -2
```

getwfk2 1

getden2 1

tolwfr2 1.0d-21

#########################################################

# Definition of the Hartree-Fock calculation

##########################################################

paral_kgb3 0

```
ixc3 -428 # Calculation with HSE06 functional
```

getwfk3 2 # Start from previous wavefunctions to ease convergence

fock_icutcoul3 5

rcut3 9.090909

#Additional (and facultative) variables for Hartree-Fock

nnsclohf3 1 # always 1 for exact exchange

nkpthf3 128 # number of k-point in the full-BZ

```
nband3 64
```

nbandhf3 46 # number of occupied states

# MG These variables are needed to run the test in parallel (bug or feature?)

np_spkpt3 32 # Number of processors for k-point parallelization

nphf3 32 # Number of processors for occupied states parallelization

# The calculation thus requires np_spkpt*nphf processors.

toldfe3 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)

optcell3 2

ionmov3 2

#getcell3 0

#getxred3 2

ntime3 150

dilatmx3 1.10

ecutsm3 0.5

tolmxf3 1.00d-6

strprecon3 0.5

prtposcar3 1 # Print out VASP-style POSCAR and FORCES for PHON and frophon

Thanks,

Moe