TREXIO Backend Comparison¶

CHAMP supports both the HDF5 (binary, high performance) and Text (human-readable) backends of the TREXIO library. This example demonstrates that calculations are invariant to the choice of backend.

Test Workflow¶

The calculation performs a short VMC run on Butadiene using identical wavefunctions stored in HDF5 and Text formats.

1. HDF5 Run¶

Input File: vmc_opt_ci1010_pVTZ_1522_hdf5.inp

%module general
    title           'butadiene'
    pool            'pool/'
    backend         hdf5
    mode            vmc_one_mpi
    pseudopot       BFD
%endmodule

load trexio          gamess_butadiene_ci1010_pVTZ.hdf5
load jastrow         jastrow_good_b3lyp.0
load jastrow_der     jastrow.der

%module electrons
   nup     11
   nelec   22
%endmodule 

%module blocking_vmc
    vmc_nstep     10
    vmc_nblk      10
    vmc_nblkeq    1
    vmc_nconf_new 0
%endmodule

2. Text Run¶

Input File: vmc_opt_ci1010_pVTZ_1522_text.inp

The input is identical except for the backend keyword and the file extension.

%module general
    title           'butadiene'
    backend         text     # text backend
    # ...
%endmodule

load trexio         gamess_butadiene_ci1010_pVTZ.trexio  # Directory name (text format)
# ...

Validation¶

The total energy and its error bars should check out to be statistically consistent between the two runs.

Resources: Backend Comparison Test