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Water DMC with TREXIO

This tutorial demonstrates a Diffusion Monte Carlo (DMC) calculation for the Water molecule using the TREXIO input format and a 2-body Jastrow factor. This complements the VMC optimization tutorial.

System Configuration

  • Molecule: Water (\(H_2O\))
  • Format: TREXIO (HDF5)
  • Method: DMC (dmc_one_mpi1)
  • Jastrow: 2-body

Input File Setup

Input File: dmc_h2o_dft_jas2body_tau0.05.inp

%module general
    title           'H2O DFT calculation'
    pool            './pool/'
    mode            'dmc_one_mpi1'
%endmodule

load trexio          H2O_DFT.hdf5
load orbitals        champ_v3_trexio_order_orbitals.lcao
load basis_num_info  $pool/champ_v3_champ_v2_trexio_H2O_DFT_with_g_basis_pointers.bfinfo
load jastrow         jastrow.final_optall

%module electrons
    nup           4
    nelec         8
%endmodule

%module blocking_dmc
    dmc_nstep     60
    dmc_nblk      40
    dmc_nblkeq    1
    dmc_nconf     100
%endmodule

%module dmc
    tau           0.05d0
    etrial      -17.26d0
    icasula      -1
%endmodule

Description

This test runs a standard DMC simulation. The load trexio command is used along with explicit loading of orbitals and basis info (demonstrating how to override or supplement TREXIO data if needed, though often TREXIO is self-contained).

Resources: DMC TREXIO Water Test