8.1. Generation of interaction files using StdFace library

8.1.1. Compile StdFace library

The interaction definition files can be generated easily using StdFace library. We will provide a short instruction how to use it.

The source package of StdFace library that supports input formats of the Hwave is available from the repository as follows.

$ git clone https://github.com/issp-center-dev/StdFace.git

Then, the library is to be compiled with the commands:

$ cd StdFace
$ mkdir build && cd build
$ cmake -DHWAVE=ON ..
$ make

If the compilation is successful, you can find the executable module hwave_dry.out in src directory.

An input to hwave_dry.out can be found as stan.in in the sample directory, which reads:

model = "Hubbard"
lattice = "square"
W = 4
L = 4
t = 1.0
t' = 0.5
U = 4.0
V = 1.0
Ncond = 16
eps = 12
calcmode = "uhfk"
exportall = 0

  • model is a keyword to choose the target model. Currently, only Hubbard is supported that denotes Hubbard model with the number of electrons fixed.

  • lattice is a keyword to specify the lattice structure. In this example, the square lattice square is chosen. W and L denote the size of the lattice.

  • t and V denote parameters of the hopping and the neighbor-site Coulomb interaction, respectively.

  • calcmode = "uhfk" and calcmode = "rpa" specify the output to be in the Wannier90(-like) format. calcmode = "uhfr" specifies the output for input files of UHFr. The default is calcmode = "uhfk". If exportall = 0 is given, the outputs are compactified with zero components omitted.

See Section Input files for UHFr , Input files for UHFk , Input files for RPA for the details of input files.

8.1.2. Run StdFace library

Then, run hwave_dry.out with the file above as an input:

$ cd path_to_Hwave/docs/tutorial/Hubbard/RPA
$ ln -s path_to_Stdface/build/src/hwave_dry.out .
$ ./uhf_dry.out stan.in

When the program finishes, a geometry information file geom.dat and interaction definition files transfer.dat and coulombinter.dat, are generated in the current directory.