Prepare the dataset
To perform efficient ab initio electronic structure calculation by DeepH method for a class of large-scale material systems, one needs to design an appropriate dataset of small structures that have close chemical bonding environment with the target large-scale material systems. Therefore, the first step of a DeepH study is to perform the DFT calculation on the above dataset to get the DFT Hamiltonian matrices with the localized basis. DeepH-pack supports DFT results made by ABACUS, OpenMX, FHI-aims or SIESTA and will support HONPAS soon.
Using ABACUS
One needs to perform the DFT calculation with ABACUS to get the Kohn-Sham Hamiltonian output file in the csr format. This output file should be placed in a separate folder for each structure in the dataset. In order to get this csr file, the input file of ABACUS should include keywords like this:
out_mat_hs2 1
Using OpenMX
One needs to perform the DFT calculation with OpenMX
to get the Kohn-Sham Hamiltonian output file in a binary
form. This binary file should be placed in a separate
folder for each structure in the dataset and should be
named as openmx.scfout
. In order to get this binary file,
the input file of OpenMX should include keywords like this:
System.Name openmx
HS.fileout On
Besides, it is required to attach the text output of
openmx.out
to the end of openmx.scfout
, which
means to run:
cat openmx.out >> openmx.scfout
Using FHI-aims
One needs to perform the DFT calculation with modified FHI-aims to get the Kohn-Sham Hamiltonian output file in text format. This output file should be placed in a separate folder for each structure in the dataset.
Using SIESTA
One needs to perform DFT calculation with SIESTA to get Hamiltonians in binary
file named ${System_name}.HSX
. To activate this feature, you should include
keyword in ${System_name}.fdf
file:
SaveHS true
It is also recommended to specify a higher convergence criteria for SCF calculation.
We found it sufficient to write in ${System_name}.fdf
file:
DM.Tolerence 1.d-9