main.py

from pyscf_TDDFT_ris import TDDFT_ris, readMO
import argparse

def str2bool(str):
    if str.lower() in ('yes', 'true', 't', 'y', '1'):
        return True
    elif str.lower() in ('no', 'false', 'f', 'n', '0'):
        return False
    else:
        raise argparse.ArgumentTypeError('Unsupported value encountered.')

def gen_args():
    parser = argparse.ArgumentParser(description='Davidson')
    parser.add_argument('-f',    '--filename',    type=str,   default=None,      help='.fch filename (molecule.fch)')
    parser.add_argument('-fout',    '--outname',     type=str,   default=None,      help='output file name')
    parser.add_argument('-func', '--functional',  type=str,   default=None,      help='functional name (pbe0)')
    parser.add_argument('-b',    '--basis',       type=str,   default=None,      help='basis set name (def2-SVP)')
    parser.add_argument('-ax',   '--a_x',         type=float, default=None,      help='HF component in the hybrid functional')
    parser.add_argument('-w',    '--omega',       type=float, default=None,      help='screening factor in the range-separated functional')
    parser.add_argument('-al',   '--alpha',       type=float, default=None,      help='alpha in the range-separated functional')
    parser.add_argument('-be',   '--beta',        type=float, default=None,      help='beta in the range-separated functional')
    
    parser.add_argument('-th',   '--theta',       type=int,   default=0.2,       help='exponent = theta/R^2, optimal theta = 0.2')
    parser.add_argument('-p',    '--add_p',       type=str2bool,  default=False,     help='add an extra p function to the auxilibary basis')

    parser.add_argument('-tda',  '--TDA',         type=str2bool,  default=False,    help='peform TDA calculation instead of TDDFT') 
    parser.add_argument('-n',    '--nroots',      type=int,   default=20,        help='the number of states you want to solve')
    parser.add_argument('-t',    '--conv_tol',    type=float,  default=1e-5,      help='the convengence tolerance in the Davidson diagonalization')
    parser.add_argument('-i',    '--max_iter',    type=int,   default=20,        help='the number of iterations in the Davidson diagonalization')
    parser.add_argument('-pt',   '--print_thre',  type=float,   default=0.05,        help='the threshold of printing the transition coefficients')

    args = parser.parse_args()

    if args.filename == None:
        raise ValueError('I need the .fch filename, such as -f molecule.fch')
    if args.functional == None and args.a_x == None and args.omega == None:
        raise ValueError('I need the functional name, such as -func pbe0; or functional parameters: a_x, omega, alpha, beta, such as -ax 0.25; -w 0.5 -al 0.5 -be 1.0')
    if args.outname == None:
        args.outname = args.filename + '-'
    else:
        args.outname = args.outname + '-'

    if args.add_p == True:
        print('using one s and one p function per atom as the auxilibary basis')
        print('You are running TDDFT-ris+p method')
    else:
        print('using one s function per atom as the auxilibary basis')
        print('You are running TDDFT-ris method')
    return args

args = gen_args()


if __name__ == '__main__':
    
    import sys,os
    print(sys.path)
    print(os.getcwd())
    '''
    if mf object already has a functional name, 
    then do not need to specify the a_x or (omega, alpha, beta), 
    as they will be read from the build-in library

    if manually specify the a_x or (omega, alpha, beta), then you dont have to input the functional name 
    '''

    ''' if args.filename ends with string .fch, use  get_mf_from_fch function '''

    if args.filename[-4:] == '.fch' :
        mf = readMO.get_mf_from_fch(fch_file=args.filename, 
                                    functional=args.functional)
    elif 'molden' in args.filename:
        if args.basis == None:
            raise ValueError('I need the basis set name, such as -b def2-TZVP. Because molden file does not provide correct basis set information.')
        mf = readMO.get_mf_from_molden(molden_file=args.filename, 
                                       functional=args.functional,
                                       basis=args.basis)
    
    td = TDDFT_ris.TDDFT_ris(mf=mf, 
                            theta=args.theta,
                            add_p=args.add_p, 
                            a_x=args.a_x,
                            omega=args.omega,
                            alpha=args.alpha,
                            beta=args.beta,
                            conv_tol=args.conv_tol,
                            nroots=args.nroots, 
                            max_iter=args.max_iter,
                            out_name=args.outname,
                            print_threshold=args.print_thre)

    if args.TDA == True:
        energies, X, oscillator_strength = td.kernel_TDA()
    else:
        energies, X, Y, oscillator_strength = td.kernel_TDDFT()