Gaussian orbital for ABACUS

About

ABACUS (Atomic-orbital Based Ab-initio Computation at UStc) supports NAO(numerical atomic orbital) as calculation basis, which is in format of ORB file. So far, NAOs are only obtained through optimazation based on jY basis. This repository supplies gaussian orbitals in ORB format, which may be needed for benchmark with other softwares.

How to use

1. Just assign the .orb file to ABACUS directly. They are converted from aims/species_defaults/non-standard/gaussian_tight_770 and cp2k/data/BASIS_MOLOPT.

NOTICE: to use them, one should modify function to_numerical_orbital_lm in ABACUS source file module_basis/module_nao/numerical_radial.cpp as following

void NumericalRadial::to_numerical_orbital_lm(Numerical_Orbital_Lm& orbital_lm, const int nk_legacy, const double lcao_dk) const
{
#ifdef __DEBUG
    assert(rgrid_);
    assert(rgrid_[0] == 0.0);
    assert(is_uniform(nr_, rgrid_, 1e-14));

    // Numerical_Orbital_Lm does not support extra exponent in the real space value
    assert(pr_ == 0);
#endif

    double dr = rgrid_[1] - rgrid_[0];
    double* rab = new double[nr_];
    std::fill(rab, rab + nr_, dr);

    //orbital_lm.set_orbital_info(symbol_, itype_, l_, izeta_, std::min(nr_, ircut_+1), rab, rgrid_,
    orbital_lm.set_orbital_info(symbol_, itype_, l_, izeta_, nr_, rab, rgrid_,
            Numerical_Orbital_Lm::Psi_Type::Psi, rvalue_, nk_legacy, lcao_dk,
            0.001 /* dr_uniform */, PARAM.inp.out_element_info, true, GlobalV::CAL_FORCE);
    delete[] rab;
}

Otherwise, the absolute value less than 1e-15 in gaussian orbital will cause different rcut and break down the calculation.

2. The script xxx2abacus_gaussian.py can generate arbitrary gaussian ORB file converted from xxx format. So far, xxx can be FHI-aims and CP2K. To use this, one can download gaussian orbital file in basis exchange and run command

python xxx2abacus_gaussian.py <inputfile> <outputfile> <rcut> [basis_label]

For example, in folder aug-cc-pVTZ-14au, run

python ../aims2abacus_gaussian.py 01_H_default 01H_augccpVTZ_14au 14

will generate 01H_augccpVTZ_14.orb and 01H_augccpVTZ_14.png.

And in folder MOLOPT-TZVP-14au, run

python ../cp2k2abacus_gaussian.py 01_H_default 01H_MOLOPT-TZVP_14au 14 MOLOPT-GTH

where MOLOPT-GTH is used to address in which line the script begins to read. The default value is MOLOPT if this parameter is not given.

3. The script check_norm.py can check whether each radial orbital is normalized.

4. The script convert.sh can run a batch of xxx2abacus_gaussian.py.