Contents

Running on a desktop

In a Jupyter notebook

import veloxchem as vlx

molecule_string = """
    O 0 0 0
    H 0 0 1.795239827225189
    H 1.693194615993441 0 -0.599043184453037"""

molecule = vlx.Molecule.read_str(molecule_string, units='angstrom')

basis = vlx.MolecularBasis.read(molecule, 'def2-svp')

scf_settings = {'conv_thresh': 1.0e-6}
method_settings = {'xcfun': 'b3lyp', 'grid_level': 4}

scfdrv = vlx.ScfRestrictedDriver()
scfdrv.update_settings(scf_settings, method_settings)
scfdrv.compute(molecule, basis)

A comprehensive presenation of how to interact and run the VeloxChem program in a Jupyter notebook is provided in the eChem book.

Using an input file

An input file driven VeloxChem calculation can be started on the command line as follows:

$ vlx water.inp [water.out]

If the optional output file name is omitted, the output will be sent to standard output.

The input file (here assumed to be named water.inp) consists of multiple groups marked with @group name and @end. For example, the following input file has three groups: jobs, method settings, and molecule.

@jobs
task: scf
@end

@method settings
xcfun: b3lyp
basis: def2-svp
@end

@molecule
charge: 0
multiplicity: 1
units: au
xyz:
O   0.0   0.0   0.0
H   0.0   1.4   1.1
H   0.0  -1.4   1.1
@end