Water with 3-Body Jastrow¶

This tutorial demonstrates the use of a 3-Body Jastrow factor (Electron-Electron-Nucleus correlation) in a VMC calculation for Water.

Input File Setup¶

Input File: vmc.inp

%module general
    title           'H2O VMC energy-only calculation with 3-body Jastrow'
    mode            vmc_one_mpi
    pseudopot       ccECP
%endmodule

load trexio         water_c2v_LDA.hdf5
load jastrow        jastrow_3body.jas    # Explicit 3-body Jastrow file
load determinants   single.det

%module blocking_vmc
    vmc_nstep     60
    vmc_nblk      1000
%endmodule

Jastrow Files¶

The jastrow_3body.jas file typically contains sections for all three correlation types: 1. e-n (1-body) 2. e-e (2-body) 3. e-e-n (3-body)

Including 3-body terms significantly improves the quality of the wavefunction and reduces the variance.

Resources: Water 3-Body Test