Using a single trexio file as input

We can use trexio file (in hdf5 or text backend format) to specify all the inputs (except Jastrow and Jastrow derivatives)

A sample input file would look like:

%module general
    title           'VMC Calculation for a molecule'
    pool            './pool/'
    mode            'vmc'
    seed            1138139413245321
    ipr -1
%endmodule

load trexio          molecule.hdf5
load jastrow         jastrow.jas
load jastrow_der     jastrow.der

%module electrons
    nup           20
    nelec         40
%endmodule


%module blocking_vmc
    vmc_nstep     20
    vmc_nblk      100000
    vmc_nblkeq    1
    vmc_nconf_new 0
%endmodule

Obtaining a trexio file from GAMESS-US output

Make sure that the recent version of trexio_tools has been installed.

pip install trexio_tools

This will provide trexio executable in the path. Use the following command to generate a trexio file.

trexio convert-from --type gamess --input gamess.out --motype "RHF"  --back_end=HDF5 sample.hdf5

Allowed values of MOtype are 'RHF', 'ROHF', 'MCSCF', 'NATURAL', 'GUGA' ...

Use trexio --help for a verbose list of options.

Converting TREXIO file into text inputs

The trexio file can be converted into several text files to be used with CHAMP. The python converter is provided in the CHAMP’s repository in the champ/tools/trex_tools folder.

A sample script is given below:

python3 /home/user/champ/tools/trex_tools/trex2champ.py \
	--trex 	"COH2_GS.trexio" \
	--backend	"HDF5" \
	--basis_prefix  "BFD-aug-cc-pVDZ" \
	--lcao \
	--ecp \
	--sym \
	--geom \
	--basis \
	--det

Use python3 trex2champ.py --help for a verbose list of options.